css-fonts/Fonts.html

Thu, 29 Aug 2013 13:06:29 +0900

author
John Daggett <jdaggett@mozilla.com>
date
Thu, 29 Aug 2013 13:06:29 +0900
changeset 8968
1c284112685e
parent 8957
b3ad55a4d7fc
child 8969
ad86f2dbd235
permissions
-rw-r--r--

[css3-fonts] remove auto value for font-size-adjust

jdaggett@484 1 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN"
jdaggett@484 2 "http://www.w3.org/TR/html4/strict.dtd">
jdaggett@484 3
jdaggett@484 4 <html lang=en>
jdaggett@484 5 <head><meta content="text/html;charset=utf-8" http-equiv=Content-Type>
jdaggett@484 6
jdaggett@1244 7 <title>CSS Fonts Module Level 3</title>
jdaggett@484 8 <!--
jdaggett@484 9 FIXME when publishing: copy the current default.css and link to
jdaggett@484 10 "default.css" rather than "../default.css"
jdaggett@484 11 -->
jdaggett@484 12 <link href="../default.css" rel=stylesheet type="text/css">
jdaggett@8699 13 <link href="../csslogo.ico" rel="shortcut icon" type="image/x-icon">
jdaggett@4546 14 <!-- I'm just experimenting here, don't get your bee in a bonnet -->
jdaggett@4546 15 <script src="http://use.typekit.com/xon2bky.js"
jdaggett@4546 16 type="text/javascript"></script>
jdaggett@4546 17 <script type="text/javascript">try{Typekit.load();}catch(e){}</script>
jdaggett@484 18
jdaggett@497 19 <style type="text/css">
jdaggett@4546 20
jdaggett@4547 21 body, th, td, h1, h2, h3, h4, h5, h6 {
jdaggett@4547 22 font-family: "myriad-pro", sans-serif !important;
jdaggett@4547 23 }
jdaggett@8277 24
jdaggett@524 25 body {
jdaggett@524 26 padding: 2em 70px 2em 70px;
jdaggett@524 27 }
jdaggett@4546 28
jdaggett@497 29 p + p, p.mtb {
jdaggett@497 30 margin-top: 0.8em;
jdaggett@497 31 text-indent: 0px;
jdaggett@497 32 }
jdaggett@6651 33
jdaggett@6651 34 #bolderlighter {
jdaggett@6651 35 width: 40%;
jdaggett@6651 36 }
jdaggett@6651 37
jdaggett@6651 38 #bolderlighter th {
jdaggett@6651 39 text-align: center;
jdaggett@6651 40 }
jdaggett@8277 41
jdaggett@7103 42 #fontformats td, #eventhandlers td, #fontformats th, #eventhandlers th {
jdaggett@1244 43 padding-right: 2em;
jdaggett@512 44 text-align: left;
jdaggett@512 45 }
jdaggett@8277 46
jdaggett@518 47 dd {
jdaggett@518 48 margin-bottom: 1em;
jdaggett@514 49 }
jdaggett@8277 50
jdaggett@516 51 #authors dd {
jdaggett@516 52 margin-bottom: 0;
jdaggett@516 53 }
jdaggett@8277 54
jdaggett@531 55 #fontstylematchingalg {
jdaggett@531 56 list-style-type: lower-alpha;
jdaggett@531 57 }
jdaggett@8277 58
jdaggett@531 59 #fontmatchingalg ul, #fontmatchingalg ol {
jdaggett@531 60 margin-top: 0.8em;
jdaggett@531 61 }
jdaggett@8277 62
jdaggett@531 63 #fontmatchingalg li + li {
jdaggett@531 64 margin-top: 0.8em;
jdaggett@531 65 }
jdaggett@8277 66
jdaggett@531 67 div.example {
jdaggett@531 68 padding: 1em;
jdaggett@531 69 margin-top: 1em;
jdaggett@531 70 }
jdaggett@531 71
jdaggett@531 72 div.example + div.example {
jdaggett@531 73 margin-top: 2em;
jdaggett@531 74 }
jdaggett@8277 75
jdaggett@531 76 div.figure {
jdaggett@531 77 page-break-inside: avoid;
jdaggett@531 78 }
jdaggett@1244 79
jdaggett@1662 80 pre.prod { white-space: pre-wrap; margin: 1em 0 1em 2em }
jdaggett@8277 81
jdaggett@8277 82 div.featex {
jdaggett@1662 83 width: 700px;
jdaggett@1662 84 }
jdaggett@8277 85
jdaggett@1662 86 div.featex img {
jdaggett@1662 87 margin: auto;
jdaggett@1662 88 display: block;
jdaggett@1662 89 }
jdaggett@6436 90
jdaggett@6436 91 span.tag {
jdaggett@6436 92 font-family: monospace;
jdaggett@6436 93 font-size: 120%;
jdaggett@6436 94 }
jdaggett@6648 95
jdaggett@6701 96 ol ol {
jdaggett@6701 97 list-style-type: lower-alpha;
jdaggett@6701 98 }
jdaggett@7060 99
jdaggett@7060 100 .idl-code {
jdaggett@7060 101 font-weight: bold;
jdaggett@7060 102 color: #c50;
jdaggett@7060 103 }
jdaggett@497 104 </style>
jdaggett@2556 105 <link href="http://www.w3.org/StyleSheets/TR/W3C-ED.css" rel=stylesheet
jdaggett@2556 106 type="text/css">
peter@8369 107 <script defer=defer
jdaggett@8385 108 src="http://test.csswg.org/harness/annotate.js#CSS3-FONTS_DEV"
jdaggett@8385 109 type="text/javascript"></script>
jdaggett@497 110
jdaggett@484 111 <body>
jdaggett@484 112 <div class=head> <!--begin-logo-->
jdaggett@484 113 <p><a href="http://www.w3.org/"><img alt=W3C height=48
jdaggett@890 114 src="http://www.w3.org/Icons/w3c_home" width=72></a> <!--end-logo-->
jdaggett@890 115
jdaggett@901 116 <h1>CSS Fonts Module Level 3</h1>
jdaggett@901 117
jdaggett@8968 118 <h2 class="no-num no-toc" id=editors-draft-29-august-2013>Editor's Draft
jdaggett@8968 119 29 August 2013</h2>
jdaggett@484 120
jdaggett@516 121 <dl id=authors>
jdaggett@484 122 <dt>This version:
jdaggett@484 123
jdaggett@484 124 <dd><a
jdaggett@8699 125 href="http://dev.w3.org/csswg/css-fonts/">http://dev.w3.org/csswg/css-fonts/</a>
jdaggett@8968 126 <!-- <dd><a href="http://www.w3.org/TR/2013/ED-css-fonts-3-20130829/">http://www.w3.org/TR/2013/ED-css-fonts-3-20130829/</a> -->
jdaggett@8699 127
jdaggett@484 128
jdaggett@484 129 <dt>Latest version:
jdaggett@484 130
jdaggett@484 131 <dd><a
jdaggett@8699 132 href="http://www.w3.org/TR/css-fonts-3/">http://www.w3.org/TR/css-fonts-3/</a>
jdaggett@484 133
jdaggett@890 134 <dt>Latest editor's draft:
jdaggett@890 135
jdaggett@890 136 <dd><a
jdaggett@8031 137 href="http://dev.w3.org/csswg/css-fonts/">http://dev.w3.org/csswg/css-fonts/</a>
jdaggett@7488 138 (<a
jdaggett@8031 139 href="https://dvcs.w3.org/hg/csswg/log/tip/css-fonts/Fonts.html">change
jdaggett@7488 140 log</a>)
jdaggett@890 141
jdaggett@4624 142 <dt>Previous version:
jdaggett@890 143
jdaggett@890 144 <dd><a
jdaggett@8699 145 href="http://www.w3.org/TR/2013/WD-css-fonts-3-20130711/">http://www.w3.org/TR/2013/WD-css-fonts-3-20130711/</a>
jdaggett@4624 146
jdaggett@4624 147 <dt>Issues List:
jdaggett@4624 148
jdaggett@4624 149 <dd><a href="http://www.w3.org/Style/CSS/Tracker/products/18">CSS3 Fonts
jdaggett@4624 150 issues in Tracker</a>
jdaggett@2556 151
jdaggett@2556 152 <dd><a
jdaggett@6648 153 href="https://www.w3.org/Bugs/Public/buglist.cgi?query_format=advanced&amp;product=CSS&amp;component=Fonts&amp;bug_status=NEW&amp;bug_status=ASSIGNED&amp;bug_status=REOPENED">CSS3
jdaggett@4624 154 Fonts issues in Bugzilla</a>
jdaggett@4624 155
jdaggett@8031 156 <dt>Discussion:
jdaggett@8031 157
jdaggett@8031 158 <dd><a
jdaggett@8031 159 href="mailto:www-style@w3.org?subject=%5Bcss-fonts%5D%20feedback">www-style@w3.org</a>
jdaggett@8031 160 with subject line “<kbd>[css-fonts] <var>… message topic
jdaggett@8031 161 …</var></kbd>” (<a
jdaggett@8031 162 href="http://lists.w3.org/Archives/Public/www-style/"
jdaggett@8031 163 rel=discussion>archives</a>)
jdaggett@890 164
jdaggett@890 165 <dt>Editor:
jdaggett@484 166
jdaggett@497 167 <dd><a href="mailto:jdaggett@mozilla.com">John Daggett (Mozilla)</a>
jdaggett@484 168 </dl>
jdaggett@484 169 <!--begin-copyright-->
jdaggett@484 170 <p class=copyright><a
jdaggett@484 171 href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright"
jdaggett@7179 172 rel=license>Copyright</a> © 2013 <a href="http://www.w3.org/"><abbr
jdaggett@5530 173 title="World Wide Web Consortium">W3C</abbr></a><sup>®</sup> (<a
jdaggett@5530 174 href="http://www.csail.mit.edu/"><abbr title="Massachusetts Institute of
jdaggett@5530 175 Technology">MIT</abbr></a>, <a href="http://www.ercim.eu/"><abbr
jdaggett@1662 176 title="European Research Consortium for Informatics and
jdaggett@7244 177 Mathematics">ERCIM</abbr></a>, <a href="http://www.keio.ac.jp/">Keio</a>,
jdaggett@7244 178 <a href="http://ev.buaa.edu.cn/">Beihang</a>), All Rights Reserved. W3C
jdaggett@7244 179 <a
jdaggett@484 180 href="http://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer">liability</a>,
jdaggett@484 181 <a
jdaggett@484 182 href="http://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks">trademark</a>
jdaggett@484 183 and <a
jdaggett@484 184 href="http://www.w3.org/Consortium/Legal/copyright-documents">document
jdaggett@484 185 use</a> rules apply.</p>
jdaggett@484 186 <!--end-copyright-->
jdaggett@484 187 <hr title="Separator for header">
jdaggett@484 188 </div>
jdaggett@525 189
jdaggett@484 190 <h2 class="no-num no-toc" id=abstract>Abstract</h2>
jdaggett@484 191
jdaggett@890 192 <p>This CSS3 module describes how font properties are specified and how
jdaggett@890 193 font resources are loaded dynamically. The contents of this specification
jdaggett@1244 194 are a consolidation of content previously divided into <a
jdaggett@3538 195 href="http://www.w3.org/TR/2002/WD-css3-fonts-20020802/">CSS3 Fonts</a>
jdaggett@3538 196 and <a href="http://www.w3.org/TR/2002/WD-css3-webfonts-20020802/">CSS3
jdaggett@7521 197 Web Fonts</a> modules. The description of font load events was moved into
jdaggett@8646 198 the <a href="http://dev.w3.org/csswg/css-font-load-events/">CSS3 Font Load
jdaggett@8646 199 Events</a> module.
jdaggett@484 200
jdaggett@484 201 <h2 class="no-num no-toc" id=status>Status of this document</h2>
jdaggett@484 202 <!--begin-status-->
jdaggett@484 203
jdaggett@484 204 <p>This is a public copy of the editors' draft. It is provided for
jdaggett@484 205 discussion only and may change at any moment. Its publication here does
jdaggett@484 206 not imply endorsement of its contents by W3C. Don't cite this document
jdaggett@484 207 other than as work in progress.
jdaggett@484 208
jdaggett@484 209 <p>The (<a
jdaggett@484 210 href="http://lists.w3.org/Archives/Public/www-style/">archived</a>) public
jdaggett@1662 211 mailing list <a
jdaggett@1662 212 href="mailto:www-style@w3.org?Subject=%5Bcss3-fonts%5D%20PUT%20SUBJECT%20HERE">
jdaggett@1662 213 www-style@w3.org</a> (see <a
jdaggett@1662 214 href="http://www.w3.org/Mail/Request">instructions</a>) is preferred for
jdaggett@1662 215 discussion of this specification. When sending e-mail, please put the text
jdaggett@1662 216 “css3-fonts” in the subject, preferably like this:
jdaggett@1148 217 “[<!---->css3-fonts<!---->] <em>…summary of comment…</em>”
jdaggett@484 218
jdaggett@8031 219 <p>This document was produced by the <a
jdaggett@8031 220 href="http://www.w3.org/Style/CSS/members">CSS Working Group</a> (part of
jdaggett@8031 221 the <a href="http://www.w3.org/Style/">Style Activity</a>).
jdaggett@484 222
jdaggett@484 223 <p>This document was produced by a group operating under the <a
jdaggett@8031 224 href="http://www.w3.org/Consortium/Patent-Policy-20040205/">5 February
jdaggett@8031 225 2004 W3C Patent Policy</a>. W3C maintains a <a
jdaggett@8031 226 href="http://www.w3.org/2004/01/pp-impl/32061/status"
jdaggett@484 227 rel=disclosure>public list of any patent disclosures</a> made in
jdaggett@484 228 connection with the deliverables of the group; that page also includes
jdaggett@484 229 instructions for disclosing a patent. An individual who has actual
jdaggett@484 230 knowledge of a patent which the individual believes contains <a
jdaggett@8031 231 href="http://www.w3.org/Consortium/Patent-Policy-20040205/#def-essential">Essential
jdaggett@484 232 Claim(s)</a> must disclose the information in accordance with <a
jdaggett@8031 233 href="http://www.w3.org/Consortium/Patent-Policy-20040205/#sec-Disclosure">section
jdaggett@8031 234 6 of the W3C Patent Policy</a>.</p>
jdaggett@484 235 <!--end-status-->
jdaggett@8385 236
jdaggett@8385 237 <h3 class="no-num no-toc" id=atrisk>Features at risk</h3>
jdaggett@8385 238
jdaggett@8385 239 <p>The following features are at risk and may be removed when exiting CR:
jdaggett@8385 240
jdaggett@8385 241 <ul>
jdaggett@8386 242 <li>fallback handling for text decoration in superscript/subscript variant
jdaggett@8385 243 glyphs (‘<a href="#propdef-font-variant-position"><code
jdaggett@8385 244 class=property>font-variant-position</code></a>’)
jdaggett@8385 245
jdaggett@8385 246 <li>‘<a href="#propdef-font-language-override"><code
jdaggett@8385 247 class=property>font-language-override</code></a>’ property
jdaggett@8385 248 </ul>
jdaggett@8699 249 <!--
jdaggett@8699 250 <p>This draft is a <strong>Last Call Working Draft</strong>.
jdaggett@8699 251 Please send comments to the
jdaggett@8699 252 <a href="http://lists.w3.org/Archives/Public/www-style/">www-style mailing list</a>
jdaggett@8699 253 as described above. The <strong>deadline for comments</strong>
jdaggett@8699 254 is six weeks after the date of publication in the header, 22 August 2013.</p>
jdaggett@8699 255 -->
jdaggett@2472 256
jdaggett@484 257 <h2 class="no-num no-toc" id=contents>Table of contents</h2>
jdaggett@484 258 <!--begin-toc-->
jdaggett@484 259
jdaggett@484 260 <ul class=toc>
jdaggett@890 261 <li><a href="#introduction"><span class=secno>1 </span>Introduction</a>
jdaggett@890 262
jdaggett@1244 263 <li><a href="#typography-background"><span class=secno>2 </span>Typography
jdaggett@545 264 Background</a>
jdaggett@545 265
jdaggett@6699 266 <li><a href="#basic-font-props"><span class=secno>3 </span>Basic Font
jdaggett@6699 267 Properties</a>
jdaggett@484 268 <ul class=toc>
jdaggett@1662 269 <li><a href="#font-family-prop"><span class=secno>3.1 </span>Font
jdaggett@1662 270 family: the font-family property</a>
jdaggett@514 271 <ul class=toc>
jdaggett@1244 272 <li><a href="#generic-font-families"><span class=secno>3.1.1
jdaggett@1244 273 </span>Generic font families</a>
jdaggett@514 274 </ul>
jdaggett@484 275
jdaggett@1662 276 <li><a href="#font-weight-prop"><span class=secno>3.2 </span>Font
jdaggett@1662 277 weight: the font-weight property</a>
jdaggett@1662 278
jdaggett@1662 279 <li><a href="#font-stretch-prop"><span class=secno>3.3 </span>Font
jdaggett@1662 280 width: the font-stretch property</a>
jdaggett@1662 281
jdaggett@1662 282 <li><a href="#font-style-prop"><span class=secno>3.4 </span>Font style:
jdaggett@1662 283 the font-style property</a>
jdaggett@1662 284
jdaggett@1662 285 <li><a href="#font-size-prop"><span class=secno>3.5 </span>Font size:
jdaggett@1662 286 the font-size property</a>
jdaggett@1662 287
jdaggett@1662 288 <li><a href="#font-size-adjust-prop"><span class=secno>3.6
jdaggett@1662 289 </span>Relative sizing: the font-size-adjust property</a>
jdaggett@1662 290
jdaggett@1662 291 <li><a href="#font-prop"><span class=secno>3.7 </span>Shorthand font
jdaggett@1662 292 property: the font property</a>
jdaggett@2457 293
jdaggett@2487 294 <li><a href="#font-synthesis-prop"><span class=secno>3.8
jdaggett@2487 295 </span>Controlling synthetic faces: the font-synthesis property</a>
jdaggett@484 296 </ul>
jdaggett@484 297
jdaggett@890 298 <li><a href="#font-resources"><span class=secno>4 </span>Font
jdaggett@6699 299 Resources</a>
jdaggett@512 300 <ul class=toc>
jdaggett@1662 301 <li><a href="#font-face-rule"><span class=secno>4.1 </span>The
jdaggett@7096 302 <code>@font-face</code> rule</a>
jdaggett@1244 303
jdaggett@1662 304 <li><a href="#font-family-desc"><span class=secno>4.2 </span>Font
jdaggett@1662 305 family: the font-family descriptor</a>
jdaggett@1662 306
jdaggett@1662 307 <li><a href="#src-desc"><span class=secno>4.3 </span>Font reference: the
jdaggett@1662 308 src descriptor</a>
jdaggett@1662 309
jdaggett@1662 310 <li><a href="#font-prop-desc"><span class=secno>4.4 </span>Font property
jdaggett@1662 311 descriptors: the font-style, font-weight, font-stretch descriptors</a>
jdaggett@1662 312
jdaggett@1662 313 <li><a href="#unicode-range-desc"><span class=secno>4.5 </span>Character
jdaggett@1662 314 range: the unicode-range descriptor</a>
jdaggett@1662 315
jdaggett@8225 316 <li><a href="#composite-fonts"><span class=secno>4.6 </span>Using
jdaggett@8225 317 character ranges to define composite fonts</a>
jdaggett@8225 318
jdaggett@8225 319 <li><a href="#font-rend-desc"><span class=secno>4.7 </span>Font
jdaggett@1732 320 features: the font-variant and font-feature-settings descriptors</a>
jdaggett@2563 321
jdaggett@8225 322 <li><a href="#font-face-loading"><span class=secno>4.8 </span>Font
jdaggett@2563 323 loading guidelines</a>
jdaggett@2737 324
jdaggett@8863 325 <li><a href="#font-fetching-requirements"><span class=secno>4.9
jdaggett@8863 326 </span>Font fetching requirements</a>
jdaggett@512 327 </ul>
jdaggett@484 328
jdaggett@1244 329 <li><a href="#font-matching-algorithm"><span class=secno>5 </span>Font
jdaggett@6699 330 Matching Algorithm</a>
jdaggett@2457 331 <ul class=toc>
jdaggett@7309 332 <li><a href="#font-family-casing"><span class=secno>5.1 </span>Case
jdaggett@7309 333 sensitivity of font family names</a>
jdaggett@7309 334
jdaggett@7309 335 <li><a href="#font-style-matching"><span class=secno>5.2 </span>Matching
jdaggett@2457 336 font styles</a>
jdaggett@2457 337
jdaggett@7309 338 <li><a href="#cluster-matching"><span class=secno>5.3 </span>Cluster
jdaggett@6701 339 matching</a>
jdaggett@6701 340
jdaggett@7309 341 <li><a href="#char-handling-issues"><span class=secno>5.4
jdaggett@2457 342 </span>Character handling issues</a>
jdaggett@2509 343
jdaggett@7309 344 <li><a href="#font-matching-changes"><span class=secno>5.5 </span>Font
jdaggett@2509 345 matching changes since CSS 2.1</a>
jdaggett@6701 346
jdaggett@7309 347 <li><a href="#font-matching-examples"><span class=secno>5.6 </span>Font
jdaggett@6701 348 matching examples</a>
jdaggett@2457 349 </ul>
jdaggett@1244 350
jdaggett@6699 351 <li><a href="#font-rend-props"><span class=secno>6 </span>Font Feature
jdaggett@6699 352 Properties</a>
jdaggett@1662 353 <ul class=toc>
jdaggett@1856 354 <li><a href="#glyph-selection-positioning"><span class=secno>6.1
jdaggett@1856 355 </span>Glyph selection and positioning</a>
jdaggett@1856 356
jdaggett@1856 357 <li><a href="#language-specific-support"><span class=secno>6.2
jdaggett@1856 358 </span>Language-specific display</a>
jdaggett@1856 359
jdaggett@1856 360 <li><a href="#font-kerning-prop"><span class=secno>6.3 </span>Kerning:
jdaggett@1662 361 the font-kerning property</a>
jdaggett@1662 362
jdaggett@6176 363 <li><a href="#font-variant-ligatures-prop"><span class=secno>6.4
jdaggett@6176 364 </span>Ligatures: the font-variant-ligatures property</a>
jdaggett@6176 365
jdaggett@6176 366 <li><a href="#font-variant-position-prop"><span class=secno>6.5
jdaggett@3638 367 </span>Subscript and superscript forms: the font-variant-position
jdaggett@3638 368 property</a>
jdaggett@1856 369
jdaggett@2118 370 <li><a href="#font-variant-caps-prop"><span class=secno>6.6
jdaggett@2118 371 </span>Capitalization: the font-variant-caps property</a>
jdaggett@2118 372
jdaggett@2118 373 <li><a href="#font-variant-numeric-prop"><span class=secno>6.7
jdaggett@2118 374 </span>Numerical formatting: the font-variant-numeric property</a>
jdaggett@2118 375
jdaggett@2118 376 <li><a href="#font-variant-alternates-prop"><span class=secno>6.8
jdaggett@1662 377 </span>Alternates and swashes: the font-variant-alternates property</a>
jdaggett@1662 378
jdaggett@1662 379
jdaggett@2472 380 <li><a href="#font-feature-values"><span class=secno>6.9 </span>Defining
jdaggett@7096 381 font specific alternates: the <code>@font-feature-values</code>
jdaggett@7096 382 rule</a>
jdaggett@8356 383 <ul class=toc>
jdaggett@8356 384 <li><a href="#basic-syntax"><span class=secno>6.9.1 </span>Basic
jdaggett@8356 385 syntax</a>
jdaggett@8356 386
jdaggett@8356 387 <li><a href="#multi-valued-feature-value-definitions"><span
jdaggett@8356 388 class=secno>6.9.2 </span>Multi-valued feature value definitions</a>
jdaggett@8356 389 </ul>
jdaggett@2118 390
jdaggett@2118 391 <li><a href="#font-variant-east-asian-prop"><span class=secno>6.10
jdaggett@1662 392 </span>East Asian text rendering: the font-variant-east-asian
jdaggett@1662 393 property</a>
jdaggett@1662 394
jdaggett@2118 395 <li><a href="#font-variant-prop"><span class=secno>6.11 </span>Overall
jdaggett@1662 396 shorthand for font rendering: the font-variant property</a>
jdaggett@1662 397
jdaggett@2118 398 <li><a href="#font-feature-settings-prop"><span class=secno>6.12
jdaggett@2509 399 </span>Low-level font feature settings control: the
jdaggett@2509 400 font-feature-settings property</a>
jdaggett@1662 401
jdaggett@2118 402 <li><a href="#font-language-override-prop"><span class=secno>6.13
jdaggett@1732 403 </span>Font language override: the font-language-override property</a>
jdaggett@1662 404 </ul>
jdaggett@1662 405
jdaggett@6176 406 <li><a href="#font-feature-resolution"><span class=secno>7 </span>Font
jdaggett@6699 407 Feature Resolution </a>
jdaggett@6699 408 <ul class=toc>
jdaggett@6699 409 <li><a href="#default-features"><span class=secno>7.1 </span>Default
jdaggett@6699 410 features</a>
jdaggett@6699 411
jdaggett@6699 412 <li><a href="#feature-precedence"><span class=secno>7.2 </span>Feature
jdaggett@6699 413 precedence</a>
jdaggett@6699 414
jdaggett@6699 415 <li><a href="#feature-precedence-examples"><span class=secno>7.3
jdaggett@6699 416 </span>Feature precedence examples</a>
jdaggett@6699 417 </ul>
jdaggett@6699 418
jdaggett@7021 419 <li><a href="#object-model"><span class=secno>8 </span>Object Model</a>
jdaggett@7021 420 <ul class=toc>
jdaggett@7021 421 <li><a href="#om-fontface"><span class=secno>8.1 </span>The
jdaggett@7021 422 <code>CSSFontFaceRule</code> interface</a>
jdaggett@7021 423
jdaggett@7021 424 <li><a href="#om-fontfeaturevalues"><span class=secno>8.2 </span>The
jdaggett@7021 425 <code>CSSFontFeatureValuesRule</code> interface</a>
jdaggett@7021 426 </ul>
jdaggett@7021 427
jdaggett@2737 428 <li class=no-num><a href="#platform-props-to-css">Appendix A: Mapping
jdaggett@1662 429 platform font properties to CSS properties</a>
jdaggett@1662 430
jdaggett@2472 431 <li class=no-num><a href="#ch-ch-ch-changes">Changes</a>
jdaggett@2472 432 <ul class=toc>
jdaggett@8699 433 <li class=no-num><a href="#recent-changes"> Changes from the July 2013
jdaggett@8699 434 CSS3 Fonts Last Call Working Draft</a>
jdaggett@2472 435 </ul>
jdaggett@2472 436
jdaggett@529 437 <li class=no-num><a href="#acknowledgments">Acknowledgments</a>
jdaggett@529 438
jdaggett@7242 439 <li class=no-num><a href="#conformance"> Conformance</a>
jdaggett@7242 440 <ul class=toc>
jdaggett@7242 441 <li class=no-num><a href="#conventions"> Document Conventions</a>
jdaggett@7242 442
jdaggett@7242 443 <li class=no-num><a href="#conformance-classes"> Conformance Classes</a>
jdaggett@7242 444
jdaggett@7242 445
jdaggett@7242 446 <li class=no-num><a href="#partial"> Partial Implementations</a>
jdaggett@7242 447
jdaggett@7242 448 <li class=no-num><a href="#experimental"> Experimental
jdaggett@7242 449 Implementations</a>
jdaggett@7242 450
jdaggett@7242 451 <li class=no-num><a href="#testing"> Non-Experimental
jdaggett@7242 452 Implementations</a>
jdaggett@7242 453 </ul>
jdaggett@7242 454
jdaggett@484 455 <li class=no-num><a href="#references">References</a>
jdaggett@484 456 <ul class=toc>
jdaggett@1662 457 <li class=no-num><a href="#normative-references">Normative
jdaggett@1662 458 References</a>
jdaggett@1662 459
jdaggett@1662 460 <li class=no-num><a href="#other-references">Other References</a>
jdaggett@484 461 </ul>
jdaggett@484 462
jdaggett@484 463 <li class=no-num><a href="#index">Index</a>
jdaggett@484 464
jdaggett@484 465 <li class=no-num><a href="#property-index">Property index</a>
jdaggett@484 466 </ul>
jdaggett@484 467 <!--end-toc-->
jdaggett@484 468
jdaggett@890 469 <h2 id=introduction><span class=secno>1 </span>Introduction</h2>
jdaggett@545 470
jdaggett@1148 471 <p>A font provides a resource containing the visual representation of
jdaggett@1662 472 characters. At the simplest level it contains information that maps
jdaggett@1662 473 character codes to shapes (called glyphs) that represent these characters.
jdaggett@1662 474 Fonts sharing a common design style are commonly grouped into font
jdaggett@1662 475 families classified by a set of standard font properties. Within a family,
jdaggett@1662 476 the shape displayed for a given character can vary by stroke weight, slant
jdaggett@7311 477 or relative width, among others. An individual font face is described by a
jdaggett@1662 478 unique combination of these properties. For a given range of text, CSS
jdaggett@1662 479 font properties are used to select a font family and a specific font face
jdaggett@1662 480 within that family to be used when rendering that text. As a simple
jdaggett@1662 481 example, to use the bold form of Helvetica one could use:
jdaggett@1148 482
jdaggett@8277 483 <pre>body {
jdaggett@8277 484 font-family: Helvetica;
jdaggett@8277 485 font-weight: bold;
jdaggett@1148 486 }</pre>
jdaggett@1148 487
jdaggett@7311 488 <p>Font resources may be installed locally on the system on which a user
jdaggett@7311 489 agent is running or downloadable. For local font resources descriptive
jdaggett@1148 490 information can be obtained directly from the font resource. For
jdaggett@1148 491 downloadable font resources (sometimes referred to as web fonts), the
jdaggett@1148 492 descriptive information is included with the reference to the font
jdaggett@1148 493 resource.
jdaggett@1148 494
jdaggett@1148 495 <p>Families of fonts typically don't contain a single face for each
jdaggett@1148 496 possible variation of font properties. The CSS font selection mechanism
jdaggett@7311 497 describes how to match a given set of CSS font properties to a single font
jdaggett@1148 498 face.
jdaggett@890 499
jdaggett@1244 500 <h2 id=typography-background><span class=secno>2 </span>Typography
jdaggett@1244 501 Background</h2>
jdaggett@890 502
jdaggett@7311 503 <p><em>This section is non-normative.</em>
jdaggett@7311 504
jdaggett@7311 505 <p> Typographic traditions vary across the globe, so there is no unique way
jdaggett@890 506 to classify all fonts across languages and cultures. For even common Latin
jdaggett@890 507 letters, wide variations are possible:
jdaggett@497 508
jdaggett@1150 509 <div class=figure><img alt="variations in glyphs for a single character"
jdaggett@1150 510 src=aaaaaa.png>
jdaggett@890 511 <p class=caption>One character, many glyph variations
jdaggett@498 512 </div>
jdaggett@497 513
jdaggett@497 514 <p>Differences in the anatomy of letterforms is one way to distinguish
jdaggett@497 515 fonts. For Latin fonts, flourishes at the ends of a character's main
jdaggett@497 516 strokes, or serifs, can distinguish a font from those without. Similar
jdaggett@534 517 comparisons exist in non-Latin fonts between fonts with tapered strokes
jdaggett@534 518 and those using primarily uniform strokes:
jdaggett@497 519
jdaggett@1150 520 <div class=figure><img alt="serif vs. non-serifs" src=serifvssansserif.png>
jdaggett@890 521 <p class=caption>Letterforms with and without serifs
jdaggett@534 522 </div>
jdaggett@534 523
jdaggett@1150 524 <div class=figure><img alt="serif vs. non-serifs for japanese"
jdaggett@1150 525 src=minchovsgothic.png>
jdaggett@890 526 <p class=caption>Similar groupings for Japanese typefaces
jdaggett@498 527 </div>
jdaggett@497 528
jdaggett@497 529 <p>Fonts contain letterforms and the data needed to map characters to these
jdaggett@7311 530 letterforms. Often this may be a simple one-to-one mapping, but more
jdaggett@497 531 complex mappings are also possible. The use of combining diacritic marks
jdaggett@497 532 creates many variations for an underlying letterform:
jdaggett@497 533
jdaggett@1150 534 <div class=figure><img alt="diacritic marks" src=aaaaaa-diacritics.png>
jdaggett@890 535 <p class=caption>Variations with diacritic marks
jdaggett@498 536 </div>
jdaggett@525 537
jdaggett@497 538 <p>A sequence of characters can be represented by a single glyph known as a
jdaggett@497 539 ligature:
jdaggett@497 540
jdaggett@1150 541 <div class=figure><img alt="example of a fi ligature"
jdaggett@1150 542 src=final-ligature.png>
jdaggett@890 543 <p class=caption>Ligature example
jdaggett@498 544 </div>
jdaggett@497 545
jdaggett@7311 546 <p>Visual transformations based on textual context are often stylistic
jdaggett@7311 547 option in European languages. They are required to correctly render
jdaggett@7311 548 languages like Arabic, the lam and alef characters below <em>must</em> be
jdaggett@7311 549 combined when they exist in sequence:
jdaggett@497 550
jdaggett@1150 551 <div class=figure><img alt="lam alef ligature" src=lamaleflig.png>
jdaggett@890 552 <p class=caption>Required Arabic ligature
jdaggett@498 553 </div>
jdaggett@497 554
jdaggett@498 555 <p>The relative complexity of these shaping transformations requires
jdaggett@498 556 additional data within the font.
jdaggett@497 557
jdaggett@497 558 <p>Sets of font faces with various stylistic variations are often grouped
jdaggett@512 559 together into font families. In the simplest case a regular face is
jdaggett@7311 560 supplemented with bold and italic faces, but much more extensive groupings
jdaggett@7311 561 are possible. Variations in the thickness of letterform strokes, the <dfn
jdaggett@7311 562 id=weight>weight</dfn>, and the overall proportions of the letterform, the
jdaggett@7311 563 <dfn id=width>width</dfn>, are most common. In the example below, each
jdaggett@7311 564 letter uses a different font face within the Univers font family. The
jdaggett@7311 565 width used increases from top to bottom and the weight increases from left
jdaggett@7311 566 to right:
jdaggett@497 567
jdaggett@1150 568 <div class=figure><img alt="various width and weight variations within a
jdaggett@1150 569 single family" src=weightwidthvariations.png>
jdaggett@890 570 <p class=caption>Weight and width variations within a single font family
jdaggett@498 571 </div>
jdaggett@497 572
jdaggett@545 573 <p>Creating fonts that support multiple scripts is a difficult task;
jdaggett@1148 574 designers need to understand the cultural traditions surrounding the use
jdaggett@1148 575 of type in different scripts and come up with letterforms that somehow
jdaggett@1148 576 share a common theme. Many languages often share a common script and each
jdaggett@7311 577 of these languages may have noticeable stylistic differences. For example,
jdaggett@7311 578 the Arabic script is shared by Persian and Urdu and Cyrillic is used with
jdaggett@7311 579 many languages, not just Russian.
jdaggett@518 580
jdaggett@8225 581 <p>The <a href="#character-map"><em>character map</em></a> of a font
jdaggett@8225 582 defines the mapping of characters to glyphs for that font. If a document
jdaggett@8225 583 contains characters not supported by the <a href="#character-map"><em
jdaggett@8225 584 title="character map">character maps</em></a> of the fonts contained in a
jdaggett@8363 585 font family list, a user agent may use a <a
jdaggett@8363 586 href="#system-font-fallback"><em>system font fallback</em></a> procedure
jdaggett@8363 587 to locate an appropriate font that does. If no appropriate font can be
jdaggett@8363 588 found, some form of "missing glyph" character will be rendered by the user
jdaggett@8363 589 agent. System fallback can occur when the specified list of font families
jdaggett@8363 590 does not include a font that supports a given character.
jdaggett@8225 591
jdaggett@8225 592 <p>Although the <a href="#character-map"><em>character map</em></a> of a
jdaggett@8225 593 font maps a given character to a glyph for that character, modern font
jdaggett@8225 594 technologies such as OpenType and AAT (Apple Advanced Typography) provide
jdaggett@8225 595 ways of mapping a character to different glyphs based upon feature
jdaggett@8225 596 settings. Fonts in these formats allow these features to be embedded in
jdaggett@8225 597 the font itself and controlled by applications. Common typographic
jdaggett@8225 598 features which can be specified this way include ligatures, swashes,
jdaggett@8225 599 contextual alternates, proportional and tabular figures, and automatic
jdaggett@8225 600 fractions, to list just a few. For a visual overview of OpenType features,
jdaggett@8225 601 see the <a href="#OPENTYPE-FONT-GUIDE"
jdaggett@6659 602 rel=biblioentry>[OPENTYPE-FONT-GUIDE]<!--{{OPENTYPE-FONT-GUIDE}}--></a>.
jdaggett@1662 603
jdaggett@6699 604 <h2 id=basic-font-props><span class=secno>3 </span>Basic Font Properties</h2>
jdaggett@512 605
jdaggett@512 606 <p>The particular font face used to render a character is determined by the
jdaggett@515 607 font family and other font properties that apply to a given element. This
jdaggett@515 608 structure allows settings to be varied independent of each other.</p>
jdaggett@512 609 <!-- prop: font-family -->
jdaggett@484 610
jdaggett@1662 611 <h3 id=font-family-prop><span class=secno>3.1 </span>Font family: the <a
jdaggett@1662 612 href="#propdef-font-family">font-family</a> property</h3>
jdaggett@1662 613
jdaggett@8225 614 <table class=propdef id=namefont-familyvalue-ltfamily-namegt-ltg>
jdaggett@484 615 <tbody>
jdaggett@484 616 <tr>
jdaggett@484 617 <td>Name:
jdaggett@484 618
jdaggett@8278 619 <td><dfn id=propdef-font-family
jdaggett@8278 620 title="font-family!!property">font-family</dfn>
jdaggett@484 621
jdaggett@484 622 <tr>
jdaggett@484 623 <td>Value:
jdaggett@484 624
jdaggett@8225 625 <td>[ <a href="#family-name-value"><var>&lt;family-name&gt;</var></a> |
jdaggett@8225 626 <a href="#generic-family-value"><var>&lt;generic-family&gt;</var></a> ]
jdaggett@8225 627 #
jdaggett@484 628
jdaggett@484 629 <tr>
jdaggett@484 630 <td>Initial:
jdaggett@484 631
jdaggett@484 632 <td>depends on user agent
jdaggett@484 633
jdaggett@484 634 <tr>
jdaggett@484 635 <td>Applies to:
jdaggett@484 636
jdaggett@484 637 <td>all elements
jdaggett@484 638
jdaggett@484 639 <tr>
jdaggett@484 640 <td>Inherited:
jdaggett@484 641
jdaggett@484 642 <td>yes
jdaggett@484 643
jdaggett@484 644 <tr>
jdaggett@484 645 <td>Percentages:
jdaggett@484 646
jdaggett@484 647 <td>N/A
jdaggett@484 648
jdaggett@484 649 <tr>
jdaggett@484 650 <td>Media:
jdaggett@484 651
jdaggett@484 652 <td>visual
jdaggett@484 653
jdaggett@484 654 <tr>
jdaggett@1148 655 <td>Computed value:
jdaggett@484 656
jdaggett@484 657 <td>as specified
jdaggett@7377 658
jdaggett@7377 659 <tr>
jdaggett@7377 660 <td>Animatable:
jdaggett@7377 661
jdaggett@7377 662 <td>no
jdaggett@484 663 </table>
jdaggett@484 664
jdaggett@514 665 <p>This property specifies a prioritized list of font family names or
jdaggett@6694 666 generic family names. A font family defines a set of faces that vary in
jdaggett@6694 667 weight, width or slope. CSS uses the combination of a family name with
jdaggett@6694 668 other style attributes to select an individual face. Using this selection
jdaggett@6694 669 mechanism, rather than selecting a face via the style name as is often
jdaggett@6694 670 done in design applications, allows some degree of regularity in textual
jdaggett@6694 671 display when fallback occurs.
jdaggett@6694 672
jdaggett@6694 673 <p class=note>Designers should note that the CSS definition of font
jdaggett@6694 674 attributes used for selection are explicitly not intended to define a font
jdaggett@6694 675 taxonomy. A type designer's idea of a family may often extend to a set of
jdaggett@6694 676 faces that vary along axes other than just the standard axes of weight,
jdaggett@6694 677 width and slope. A family may extend to include both a set of serif faces
jdaggett@6694 678 and a set of sans-serif faces or vary along axes that are unique to that
jdaggett@6694 679 family. The CSS font selection mechanism merely provides a way to
jdaggett@6694 680 determine the “closest” substitute when substitution is necessary.
jdaggett@6694 681
jdaggett@6694 682 <p>Unlike other CSS properties, component values are a comma-separated list
jdaggett@6694 683 indicating alternatives. A user agent iterates through the list of family
jdaggett@6694 684 names until it matches an available font that contains a glyph for the
jdaggett@6694 685 character to be rendered. This allows for differences in available fonts
jdaggett@6694 686 across platforms and for differences in the range of characters supported
jdaggett@6694 687 by individual fonts.
jdaggett@514 688
jdaggett@514 689 <p>A font family name only specifies a name given to a set of font faces,
jdaggett@8177 690 it does not specify an individual face. For example, given the
jdaggett@8177 691 availability of the fonts below, Futura would match but Futura Medium
jdaggett@8177 692 would not:
jdaggett@514 693
jdaggett@1150 694 <div class=figure><img alt="family and face names"
jdaggett@1150 695 src=familyvsfacename.png>
jdaggett@890 696 <p class=caption>Family and individual face names
jdaggett@514 697 </div>
jdaggett@514 698
jdaggett@514 699 <p>Consider the example below:
jdaggett@512 700
jdaggett@512 701 <div class=example>
jdaggett@8277 702 <pre>body {
jdaggett@8277 703 font-family: Helvetica, Verdana, sans-serif;
jdaggett@514 704 }</pre>
jdaggett@1758 705
jdaggett@1758 706 <p>If Helvetica is available it will be used when rendering. If neither
jdaggett@1758 707 Helvetica nor Verdana is present, then the user-agent-defined sans serif
jdaggett@1758 708 font will be used.</p>
jdaggett@512 709 </div>
jdaggett@512 710
jdaggett@514 711 <p>There are two types of font family names:
jdaggett@512 712
jdaggett@512 713 <dl>
jdaggett@8225 714 <dt><dfn id=family-name-value><var>&lt;family-name&gt;</var></dfn>
jdaggett@514 715
jdaggett@514 716 <dd>The name of a font family of choice such as Helvetica or Verdana in
jdaggett@2457 717 the previous example.
jdaggett@514 718
jdaggett@8225 719 <dt><dfn id=generic-family-value><var>&lt;generic-family&gt;</var></dfn>
jdaggett@514 720
jdaggett@4624 721 <dd> The following generic family keywords are defined: ‘<a
jdaggett@4624 722 href="#serif"><code class=property>serif</code></a>’, ‘<a
jdaggett@4624 723 href="#sans-serif"><code class=property>sans-serif</code></a>’, ‘<a
jdaggett@4624 724 href="#cursive"><code class=property>cursive</code></a>’, ‘<a
jdaggett@4624 725 href="#fantasy"><code class=property>fantasy</code></a>’, and ‘<a
jdaggett@4624 726 href="#monospace"><code class=property>monospace</code></a>’. These
jdaggett@1148 727 keywords can be used as a general fallback mechanism when an author's
jdaggett@1758 728 desired font choices are not available. As keywords, they must not be
jdaggett@1148 729 quoted. Authors are encouraged to append a generic font family as a last
jdaggett@1148 730 alternative for improved robustness.
jdaggett@512 731 </dl>
jdaggett@512 732
jdaggett@8272 733 <p>Font family names other than generic families must either be given
jdaggett@8272 734 quoted as <a
jdaggett@8699 735 href="http://www.w3.org/TR/CSS21/syndata.html#strings">strings,</a> or
jdaggett@8699 736 unquoted as a sequence of one or more <a
bert@8683 737 href="http://www.w3.org/TR/CSS21/syndata.html#value-def-identifier">identifiers.</a>
jdaggett@2457 738 This means most punctuation characters and digits at the start of each
jdaggett@2457 739 token must be escaped in unquoted font family names.
jdaggett@2457 740
jdaggett@7377 741 <p>To illustrate this, the following declarations are invalid:
jdaggett@2457 742
jdaggett@2457 743 <pre>
jdaggett@2457 744 font-family: Red/Black, sans-serif;
jdaggett@2457 745 font-family: "Lucida" Grande, sans-serif;
jdaggett@2457 746 font-family: Ahem!, sans-serif;
jdaggett@2457 747 font-family: test@foo, sans-serif;
jdaggett@2457 748 font-family: #POUND, sans-serif;
jdaggett@2457 749 font-family: Hawaii 5-0, sans-serif;
jdaggett@2457 750 </pre>
jdaggett@2457 751
jdaggett@2457 752 <p>If a sequence of identifiers is given as a font family name, the
jdaggett@2457 753 computed value is the name converted to a string by joining all the
jdaggett@2457 754 identifiers in the sequence by single spaces.
jdaggett@2457 755
jdaggett@2457 756 <p>To avoid mistakes in escaping, it is recommended to quote font family
jdaggett@2457 757 names that contain white space, digits, or punctuation characters other
jdaggett@2457 758 than hyphens:
jdaggett@2457 759
jdaggett@2457 760 <pre>
jdaggett@2457 761 body { font-family: "New Century Schoolbook", serif }
jdaggett@2457 762
jdaggett@2457 763 &lt;BODY STYLE="font-family: '21st Century', fantasy">
jdaggett@2457 764 </pre>
jdaggett@2457 765
jdaggett@2457 766 <p>Font family <em>names</em> that happen to be the same as a keyword value
jdaggett@4624 767 (‘<code class=property>inherit</code>’, ‘<a href="#serif"><code
jdaggett@4624 768 class=property>serif</code></a>’, ‘<a href="#sans-serif"><code
jdaggett@4624 769 class=property>sans-serif</code></a>’, ‘<a href="#monospace"><code
jdaggett@4624 770 class=property>monospace</code></a>’, ‘<a href="#fantasy"><code
jdaggett@4624 771 class=property>fantasy</code></a>’, and ‘<a href="#cursive"><code
jdaggett@4624 772 class=property>cursive</code></a>’) must be quoted to prevent confusion
jdaggett@2457 773 with the keywords with the same names. The keywords ‘<code
jdaggett@2457 774 class=property>initial</code>’ and ‘<code
jdaggett@2457 775 class=property>default</code>’ are reserved for future use and must also
jdaggett@2457 776 be quoted when used as font names. UAs must not consider these keywords as
jdaggett@8225 777 matching the <a
jdaggett@8225 778 href="#family-name-value"><var>&lt;family-name&gt;</var></a> type.
jdaggett@2457 779
jdaggett@6694 780 <p>The precise way a set of fonts are grouped into font families varies
jdaggett@6694 781 depending upon the platform font management API's. The Windows GDI API
jdaggett@6694 782 only allows four faces to be grouped into a family while the DirectWrite
jdaggett@6694 783 API and API's on OSX and other platforms support font families with a
jdaggett@6695 784 variety of weights, widths and slopes (see <a
jdaggett@6694 785 href="#platform-props-to-css">Appendix A</a> for more details).
jdaggett@6694 786
jdaggett@2457 787 <p>Some font formats allow fonts to carry multiple localizations of the
jdaggett@2457 788 family name. User agents must recognize and correctly match all of these
jdaggett@2457 789 names independent of the underlying platform localization, system API used
jdaggett@2457 790 or document encoding:
jdaggett@2457 791
jdaggett@2457 792 <div class=figure><img alt="examples of localized family names"
jdaggett@2457 793 src=localizedfamilynames.png>
jdaggett@2457 794 <p class=caption>Localized family names
jdaggett@2457 795 </div>
jdaggett@2457 796
jdaggett@1244 797 <h4 id=generic-font-families><span class=secno>3.1.1 </span>Generic font
jdaggett@1244 798 families</h4>
jdaggett@514 799
jdaggett@518 800 <p>All five generic font families are defined to exist in all CSS
jdaggett@518 801 implementations (they need not necessarily map to five distinct actual
jdaggett@518 802 fonts). User agents should provide reasonable default choices for the
jdaggett@518 803 generic font families, which express the characteristics of each family as
jdaggett@518 804 well as possible within the limits allowed by the underlying technology.
jdaggett@518 805 User agents are encouraged to allow users to select alternative choices
jdaggett@514 806 for the generic fonts.
jdaggett@514 807
jdaggett@890 808 <h5 class="no-num no-toc"> <span class=index-def id=serif0 title="serif,
jdaggett@890 809 definition of"><a name=serif-def><dfn id=serif>serif</dfn></a></span></h5>
jdaggett@514 810
jdaggett@8178 811 <p>Serif fonts represent the formal text style for a script. This often
jdaggett@8178 812 means but is not limited to glyphs that have finishing strokes, flared or
jdaggett@8178 813 tapering ends, or have actual serifed endings (including slab serifs).
jdaggett@8178 814 Serif fonts are typically proportionately-spaced. They often display a
jdaggett@8178 815 greater variation between thick and thin strokes than fonts from the ‘<a
jdaggett@8178 816 href="#sans-serif"><code class=property>sans-serif</code></a>’ generic
jdaggett@8178 817 font family. CSS uses the term ‘<a href="#serif"><code
jdaggett@8178 818 class=property>serif</code></a>’ to apply to a font for any script,
jdaggett@8178 819 although other names may be more familiar for particular scripts, such as
jdaggett@8178 820 Mincho (Japanese), Sung, Song or Kai (Chinese), Batang (Korean). For
jdaggett@8178 821 Arabic, the Naskh style would correspond to ‘<a href="#serif"><code
jdaggett@8178 822 class=property>serif</code></a>’ more due to its typographic role rather
jdaggett@8178 823 than its actual design style. Any font that is so described may be used to
jdaggett@4624 824 represent the generic ‘<a href="#serif"><code
jdaggett@4624 825 class=property>serif</code></a>’ family.
jdaggett@514 826
jdaggett@1150 827 <div class=figure><img alt="sample serif fonts" src=serifexamples.png>
jdaggett@890 828 <p class=caption>Sample serif fonts
jdaggett@514 829 </div>
jdaggett@514 830
jdaggett@890 831 <h5 class="no-num no-toc"> <span class=index-def id=sans-serif0
jdaggett@890 832 title="sans-serif, definition of"> <a name=sans-serif-def><dfn
jdaggett@890 833 id=sans-serif>sans-serif</dfn></a></span></h5>
jdaggett@514 834
jdaggett@8178 835 <p>Glyphs in sans-serif fonts, as the term is used in CSS, are generally
jdaggett@8178 836 low contrast (vertical and horizontal stems have the close to the same
jdaggett@8178 837 thickness) and have stroke endings that are plain -- without any flaring,
jdaggett@8178 838 cross stroke, or other ornamentation. Sans-serif fonts are typically
jdaggett@8178 839 proportionately-spaced. They often have little variation between thick and
jdaggett@8178 840 thin strokes, compared to fonts from the ‘<a href="#serif"><code
jdaggett@4624 841 class=property>serif</code></a>’ family. CSS uses the term ‘<a
jdaggett@4624 842 href="#sans-serif"><code class=property>sans-serif</code></a>’ to apply
jdaggett@4624 843 to a font for any script, although other names may be more familiar for
jdaggett@3041 844 particular scripts, such as Gothic (Japanese), Hei (Chinese), or Gulim
jdaggett@1148 845 (Korean). Any font that is so described may be used to represent the
jdaggett@4624 846 generic ‘<a href="#sans-serif"><code
jdaggett@4624 847 class=property>sans-serif</code></a>’ family.
jdaggett@518 848
jdaggett@1150 849 <div class=figure><img alt="sample sans-serif fonts"
jdaggett@1150 850 src=sansserifexamples.png>
jdaggett@890 851 <p class=caption>Sample sans-serif fonts
jdaggett@514 852 </div>
jdaggett@514 853
jdaggett@890 854 <h5 class="no-num no-toc"> <span class=index-def id=cursive0
jdaggett@545 855 title="cursive, definition of"> <a name=cursive-def><dfn
jdaggett@890 856 id=cursive>cursive</dfn></a></span></h5>
jdaggett@545 857
jdaggett@8178 858 <p>Glyphs in cursive fonts generally use a more informal script style, and
jdaggett@8178 859 the result looks more like handwritten pen or brush writing than printed
jdaggett@8178 860 letterwork. CSS uses the term ‘<a href="#cursive"><code
jdaggett@8178 861 class=property>cursive</code></a>’ to apply to a font for any script,
jdaggett@8178 862 although other names such as Chancery, Brush, Swing and Script are also
jdaggett@8178 863 used in font names.
jdaggett@514 864
jdaggett@1150 865 <div class=figure><img alt="sample cursive fonts" src=cursiveexamples.png>
jdaggett@890 866 <p class=caption>Sample cursive fonts
jdaggett@514 867 </div>
jdaggett@514 868
jdaggett@890 869 <h5 class="no-num no-toc"> <span class=index-def id=fantasy0
jdaggett@545 870 title="fantasy, definition of"> <a name=fantasy-def><dfn
jdaggett@890 871 id=fantasy>fantasy</dfn></a></span></h5>
jdaggett@514 872
jdaggett@8178 873 <p>Fantasy fonts are primarily decorative or expressive fonts that contain
jdaggett@8178 874 playful representations of characters. These do not include Pi or Picture
jdaggett@8178 875 fonts which do not represent actual characters.
jdaggett@514 876
jdaggett@1150 877 <div class=figure><img alt="sample fantasy fonts" src=fantasyexamples.png>
jdaggett@890 878 <p class=caption>Sample fantasy fonts
jdaggett@514 879 </div>
jdaggett@514 880
jdaggett@890 881 <h5 class="no-num no-toc"> <span class=index-def id=monospace0
jdaggett@545 882 title="monospace, definition of"> <a name=monospace-def><dfn
jdaggett@890 883 id=monospace>monospace</dfn></a></span></h5>
jdaggett@514 884
jdaggett@514 885 <p>The sole criterion of a monospace font is that all glyphs have the same
jdaggett@518 886 fixed width. This is often used to render samples of computer code.
jdaggett@514 887
jdaggett@1150 888 <div class=figure><img alt="sample monospace fonts"
jdaggett@1150 889 src=monospaceexamples.png>
jdaggett@890 890 <p class=caption>Sample monospace fonts
jdaggett@514 891 </div>
jdaggett@512 892 <!-- prop: font-weight -->
jdaggett@512 893
jdaggett@1662 894 <h3 id=font-weight-prop><span class=secno>3.2 </span>Font weight: the <a
jdaggett@1662 895 href="#propdef-font-weight">font-weight</a> property</h3>
jdaggett@1662 896
jdaggett@4624 897 <table class=propdef id=namefont-weightvaluenormal-bold-bolder-l>
jdaggett@484 898 <tbody>
jdaggett@484 899 <tr>
jdaggett@484 900 <td>Name:
jdaggett@484 901
jdaggett@8278 902 <td><dfn id=propdef-font-weight
jdaggett@8278 903 title="font-weight!!property">font-weight</dfn>
jdaggett@484 904
jdaggett@484 905 <tr>
jdaggett@484 906 <td>Value:
jdaggett@484 907
jdaggett@8278 908 <td><a href="#font-weight-normal-value"
jdaggett@8278 909 title="normal!!font-weight">normal</a> | <a href="#bold">bold</a> | <a
jdaggett@8278 910 href="#bolder">bolder</a> | <a href="#lighter">lighter</a> | <a
jdaggett@8278 911 href="#font-weight-numeric-values" title="100...900 weight
jdaggett@8278 912 values">100</a> | <a href="#font-weight-numeric-values"
jdaggett@8278 913 title="100...900 weight values">200</a> | <a
jdaggett@8278 914 href="#font-weight-numeric-values" title="100...900 weight
jdaggett@8278 915 values">300</a> | <a href="#font-weight-numeric-values"
jdaggett@8278 916 title="100...900 weight values">400</a> | <a
jdaggett@8278 917 href="#font-weight-numeric-values" title="100...900 weight
jdaggett@8278 918 values">500</a> | <a href="#font-weight-numeric-values"
jdaggett@8278 919 title="100...900 weight values">600</a> | <a
jdaggett@8278 920 href="#font-weight-numeric-values" title="100...900 weight
jdaggett@8278 921 values">700</a> | <a href="#font-weight-numeric-values"
jdaggett@8278 922 title="100...900 weight values">800</a> | <a
jdaggett@8278 923 href="#font-weight-numeric-values" title="100...900 weight
jdaggett@8278 924 values">900</a>
jdaggett@484 925
jdaggett@484 926 <tr>
jdaggett@484 927 <td>Initial:
jdaggett@484 928
jdaggett@484 929 <td>normal
jdaggett@484 930
jdaggett@484 931 <tr>
jdaggett@484 932 <td>Applies to:
jdaggett@484 933
jdaggett@484 934 <td>all elements
jdaggett@484 935
jdaggett@484 936 <tr>
jdaggett@484 937 <td>Inherited:
jdaggett@484 938
jdaggett@484 939 <td>yes
jdaggett@484 940
jdaggett@484 941 <tr>
jdaggett@484 942 <td>Percentages:
jdaggett@484 943
jdaggett@484 944 <td>N/A
jdaggett@484 945
jdaggett@484 946 <tr>
jdaggett@484 947 <td>Media:
jdaggett@484 948
jdaggett@484 949 <td>visual
jdaggett@484 950
jdaggett@484 951 <tr>
jdaggett@1148 952 <td>Computed value:
jdaggett@484 953
jdaggett@8177 954 <td>numeric weight value (see description)
jdaggett@7377 955
jdaggett@7377 956 <tr>
jdaggett@7377 957 <td>Animatable:
jdaggett@7377 958
jdaggett@7377 959 <td>as <a
jdaggett@7377 960 href="http://dev.w3.org/csswg/css3-transitions/#animtype-font-weight">font
jdaggett@7377 961 weight</a>
jdaggett@484 962 </table>
jdaggett@484 963
jdaggett@8278 964 <p>The <a href="#propdef-font-weight"
jdaggett@8278 965 title="font-weight!!property">‘<code
jdaggett@8278 966 class=property>font-weight</code>’</a> property specifies the weight of
jdaggett@8278 967 glyphs in the font, their degree of blackness or stroke thickness.
jdaggett@531 968
jdaggett@531 969 <p>Values have the following meanings:
jdaggett@512 970
jdaggett@512 971 <dl>
jdaggett@8278 972 <dt><dfn id=font-weight-numeric-values title="100...900 weight values">100
jdaggett@8278 973 to 900</dfn>
jdaggett@512 974
jdaggett@512 975 <dd>These values form an ordered sequence, where each number indicates a
jdaggett@514 976 weight that is at least as dark as its predecessor. These roughly
jdaggett@514 977 correspond to the commonly used weight names below:
jdaggett@512 978 </dl>
jdaggett@512 979
jdaggett@512 980 <ul>
jdaggett@512 981 <li>100 - Thin
jdaggett@512 982
jdaggett@518 983 <li>200 - Extra Light (Ultra Light)
jdaggett@512 984
jdaggett@512 985 <li>300 - Light
jdaggett@512 986
jdaggett@512 987 <li>400 - Normal
jdaggett@512 988
jdaggett@512 989 <li>500 - Medium
jdaggett@512 990
jdaggett@518 991 <li>600 - Semi Bold (Demi Bold)
jdaggett@512 992
jdaggett@512 993 <li>700 - Bold
jdaggett@512 994
jdaggett@518 995 <li>800 - Extra Bold (Ultra Bold)
jdaggett@512 996
jdaggett@512 997 <li>900 - Black (Heavy)
jdaggett@512 998 </ul>
jdaggett@512 999
jdaggett@512 1000 <dl>
jdaggett@8278 1001 <dt><dfn id=font-weight-normal-value
jdaggett@8278 1002 title="normal!!font-weight">normal</dfn>
jdaggett@512 1003
jdaggett@1148 1004 <dd>Same as ‘<code class=css>400</code>’.
jdaggett@512 1005
jdaggett@8278 1006 <dt><dfn id=bold>bold</dfn>
jdaggett@512 1007
jdaggett@1148 1008 <dd>Same as ‘<code class=css>700</code>’.
jdaggett@512 1009
jdaggett@8278 1010 <dt><dfn id=bolder>bolder</dfn>
jdaggett@512 1011
jdaggett@8177 1012 <dd>Specifies a bolder weight than the inherited value.
jdaggett@512 1013
jdaggett@8278 1014 <dt><dfn id=lighter>lighter</dfn>
jdaggett@512 1015
jdaggett@8177 1016 <dd>Specifies a lighter weight than the inherited value.
jdaggett@512 1017 </dl>
jdaggett@512 1018
jdaggett@8177 1019 <p>Font formats that use a scale other than a nine-step scale should map
jdaggett@531 1020 their scale onto the CSS scale so that 400 roughly corresponds with a face
jdaggett@531 1021 that would be labeled as Regular, Book, Roman and 700 roughly matches a
jdaggett@531 1022 face that would be labeled as Bold. Or weights may be inferred from the
jdaggett@531 1023 style names, ones that correspond roughly with the scale above. The scale
jdaggett@1662 1024 is relative, so a face with a larger weight value must never appear
jdaggett@1148 1025 lighter. If style names are used to infer weights, care should be taken to
jdaggett@1148 1026 handle variations in style names across locales.
jdaggett@531 1027
jdaggett@531 1028 <p>Quite often there are only a few weights available for a particular font
jdaggett@534 1029 family. When a weight is specified for which no face exists, a face with a
jdaggett@534 1030 nearby weight is used. In general, bold weights map to faces with heavier
jdaggett@1269 1031 weights and light weights map to faces with lighter weights (see the <a
jdaggett@1269 1032 href="#font-matching-algorithm">font matching section below</a> for a
jdaggett@1269 1033 precise definition). The examples here illustrate which face is used for
jdaggett@1269 1034 different weights, grey indicates a face for that weight does not exist so
jdaggett@1269 1035 a face with a nearby weight is used:
jdaggett@532 1036
jdaggett@1150 1037 <div class=figure><img alt="weight mappings for a family with 400, 700 and
jdaggett@1150 1038 900 weights" src=optimaweights.png>
jdaggett@532 1039 <p class=caption>Weight mappings for a font family with 400, 700 and 900
jdaggett@890 1040 weight faces
jdaggett@518 1041 </div>
jdaggett@518 1042
jdaggett@1150 1043 <div class=figure><img alt="weight mappings for a family with 300, 600
jdaggett@1150 1044 weights" src=hiraginoweights.png>
jdaggett@532 1045 <p class=caption>Weight mappings for a font family with 300 and 600 weight
jdaggett@890 1046 faces
jdaggett@531 1047 </div>
jdaggett@518 1048
jdaggett@2487 1049 <p>Although the practice is not well-loved by typographers, bold faces are
jdaggett@2487 1050 often synthesized by user agents for faces that lack actual bold faces.
jdaggett@2487 1051 For the purposes of style matching, these faces must be treated as if they
jdaggett@8177 1052 exist within the family. Authors can explicitly avoid this behavior by
jdaggett@8177 1053 using the ‘<a href="#propdef-font-synthesis"><code
jdaggett@8177 1054 class=property>font-synthesis</code></a>’ property.
jdaggett@8177 1055
jdaggett@8278 1056 <p>Specified values of ‘<a href="#bolder"><code
jdaggett@8278 1057 class=property>bolder</code></a>’ and ‘<a href="#lighter"><code
jdaggett@8278 1058 class=property>lighter</code></a>’ indicate weights relative to the
jdaggett@8177 1059 weight of the parent element. The computed weight is calculated based on
jdaggett@8278 1060 the inherited <a href="#propdef-font-weight"
jdaggett@8278 1061 title="font-weight!!property">‘<code
jdaggett@8278 1062 class=property>font-weight</code>’</a> value using the chart below.
jdaggett@1148 1063
jdaggett@6651 1064 <table class=data id=bolderlighter summary="Bolder/lighter mappings">
jdaggett@1148 1065 <thead>
jdaggett@1148 1066 <tr>
jdaggett@6651 1067 <th>Inherited value
jdaggett@6651 1068
jdaggett@6651 1069 <th>bolder
jdaggett@6651 1070
jdaggett@6651 1071 <th>lighter
jdaggett@1148 1072
jdaggett@1148 1073 <tbody>
jdaggett@1148 1074 <tr>
jdaggett@1244 1075 <th>100
jdaggett@1148 1076
jdaggett@1148 1077 <td>400
jdaggett@1148 1078
jdaggett@1148 1079 <td>100
jdaggett@1148 1080
jdaggett@1148 1081 <tr>
jdaggett@1244 1082 <th>200
jdaggett@1148 1083
jdaggett@1148 1084 <td>400
jdaggett@1148 1085
jdaggett@1148 1086 <td>100
jdaggett@1148 1087
jdaggett@1148 1088 <tr>
jdaggett@1244 1089 <th>300
jdaggett@1148 1090
jdaggett@1148 1091 <td>400
jdaggett@1148 1092
jdaggett@1148 1093 <td>100
jdaggett@1148 1094
jdaggett@1148 1095 <tr>
jdaggett@1244 1096 <th>400
jdaggett@1148 1097
jdaggett@1148 1098 <td>700
jdaggett@1148 1099
jdaggett@1148 1100 <td>100
jdaggett@1148 1101
jdaggett@1148 1102 <tr>
jdaggett@1244 1103 <th>500
jdaggett@1148 1104
jdaggett@1148 1105 <td>700
jdaggett@1148 1106
jdaggett@1148 1107 <td>100
jdaggett@1148 1108
jdaggett@1148 1109 <tr>
jdaggett@1244 1110 <th>600
jdaggett@1148 1111
jdaggett@1148 1112 <td>900
jdaggett@1148 1113
jdaggett@1148 1114 <td>400
jdaggett@1148 1115
jdaggett@1148 1116 <tr>
jdaggett@1244 1117 <th>700
jdaggett@1148 1118
jdaggett@1148 1119 <td>900
jdaggett@1148 1120
jdaggett@1148 1121 <td>400
jdaggett@1148 1122
jdaggett@1148 1123 <tr>
jdaggett@1244 1124 <th>800
jdaggett@1148 1125
jdaggett@1148 1126 <td>900
jdaggett@1148 1127
jdaggett@1148 1128 <td>700
jdaggett@1148 1129
jdaggett@1148 1130 <tr>
jdaggett@1244 1131 <th>900
jdaggett@1148 1132
jdaggett@1148 1133 <td>900
jdaggett@1148 1134
jdaggett@1148 1135 <td>700
jdaggett@1148 1136 </table>
jdaggett@1148 1137
jdaggett@1148 1138 <p>The table above is equivalent to selecting the next relative bolder or
jdaggett@1148 1139 lighter face, given a font family containing normal and bold faces along
jdaggett@1148 1140 with a thin and a heavy face. Authors who desire finer control over the
jdaggett@8177 1141 exact weight values used for a given element may use numerical values
jdaggett@1148 1142 instead of relative weights.</p>
jdaggett@512 1143 <!-- prop: font-stretch -->
jdaggett@512 1144
jdaggett@1662 1145 <h3 id=font-stretch-prop><span class=secno>3.3 </span>Font width: the <a
jdaggett@1662 1146 href="#propdef-font-stretch">font-stretch</a> property</h3>
jdaggett@1662 1147
jdaggett@8278 1148 <table class=propdef id=namefont-stretchvalue-normal-ultra-conde>
jdaggett@484 1149 <tbody>
jdaggett@484 1150 <tr>
jdaggett@484 1151 <td>Name:
jdaggett@484 1152
jdaggett@8278 1153 <td><dfn id=propdef-font-stretch
jdaggett@8278 1154 title="font-stretch!!property">font-stretch</dfn>
jdaggett@484 1155
jdaggett@484 1156 <tr>
jdaggett@484 1157 <td>Value:
jdaggett@484 1158
jdaggett@8278 1159 <td> <a href="#font-stretch-normal-value"
jdaggett@8278 1160 title="normal!!font-stretch">normal</a> | <a
jdaggett@8278 1161 href="#ultra-condensed">ultra-condensed</a> | <a
jdaggett@8278 1162 href="#extra-condensed">extra-condensed</a> | <a
jdaggett@8278 1163 href="#condensed">condensed</a> | <a
jdaggett@8278 1164 href="#semi-condensed-">semi-condensed</a> | <a
jdaggett@8278 1165 href="#semi-expanded">semi-expanded</a> | <a
jdaggett@8278 1166 href="#expanded">expanded</a> | <a
jdaggett@8278 1167 href="#extra-expanded">extra-expanded</a> | <a
jdaggett@8278 1168 href="#ultra-expanded">ultra-expanded</a>
jdaggett@484 1169
jdaggett@484 1170 <tr>
jdaggett@484 1171 <td>Initial:
jdaggett@484 1172
jdaggett@484 1173 <td>normal
jdaggett@484 1174
jdaggett@484 1175 <tr>
jdaggett@484 1176 <td>Applies to:
jdaggett@484 1177
jdaggett@484 1178 <td>all elements
jdaggett@484 1179
jdaggett@484 1180 <tr>
jdaggett@484 1181 <td>Inherited:
jdaggett@484 1182
jdaggett@484 1183 <td>yes
jdaggett@484 1184
jdaggett@484 1185 <tr>
jdaggett@484 1186 <td>Percentages:
jdaggett@484 1187
jdaggett@484 1188 <td>N/A
jdaggett@484 1189
jdaggett@484 1190 <tr>
jdaggett@484 1191 <td>Media:
jdaggett@484 1192
jdaggett@484 1193 <td>visual
jdaggett@484 1194
jdaggett@484 1195 <tr>
jdaggett@1148 1196 <td>Computed value:
jdaggett@484 1197
jdaggett@484 1198 <td>as specified
jdaggett@7377 1199
jdaggett@7377 1200 <tr>
jdaggett@7377 1201 <td>Animatable:
jdaggett@7377 1202
jdaggett@7377 1203 <td>as <a href="#font-stretch-animation">font stretch</a>
jdaggett@484 1204 </table>
jdaggett@484 1205
jdaggett@8278 1206 <p>The <a href="#propdef-font-stretch"
jdaggett@8278 1207 title="font-stretch!!property">‘<code
jdaggett@8278 1208 class=property>font-stretch</code>’</a> property selects a normal,
jdaggett@8278 1209 condensed, or expanded face from a font family. Absolute keyword values
jdaggett@8278 1210 have the following ordering, from narrowest to widest:
jdaggett@512 1211
jdaggett@512 1212 <ul>
jdaggett@8278 1213 <li><dfn id=ultra-condensed>ultra-condensed</dfn>
jdaggett@8278 1214
jdaggett@8278 1215 <li><dfn id=extra-condensed>extra-condensed</dfn>
jdaggett@8278 1216
jdaggett@8278 1217 <li><dfn id=condensed>condensed</dfn>
jdaggett@8278 1218
jdaggett@8278 1219 <li><dfn id=semi-condensed->semi-condensed </dfn>
jdaggett@8278 1220
jdaggett@8278 1221 <li><dfn id=font-stretch-normal-value
jdaggett@8278 1222 title="normal!!font-stretch">normal</dfn>
jdaggett@8278 1223
jdaggett@8278 1224 <li><dfn id=semi-expanded>semi-expanded</dfn>
jdaggett@8278 1225
jdaggett@8278 1226 <li><dfn id=expanded>expanded</dfn>
jdaggett@8278 1227
jdaggett@8278 1228 <li><dfn id=extra-expanded>extra-expanded</dfn>
jdaggett@8278 1229
jdaggett@8278 1230 <li><dfn id=ultra-expanded>ultra-expanded</dfn>
jdaggett@512 1231 </ul>
jdaggett@512 1232
jdaggett@8197 1233 <p>When a face does not exist for a given width, normal or condensed values
jdaggett@8197 1234 map to a narrower face, otherwise a wider face. Conversely, expanded
jdaggett@8197 1235 values map to a wider face, otherwise a narrower face. The figure below
jdaggett@8197 1236 shows how the nine font-stretch property settings affect font selection
jdaggett@8197 1237 for font family containing a variety of widths, grey indicates a width for
jdaggett@8197 1238 which no face exists and a different width is substituted:
jdaggett@1148 1239
jdaggett@1150 1240 <div class=figure><img alt="width mappings for a family with condensed,
jdaggett@1150 1241 normal and expanded faces" src=universwidths.png>
jdaggett@1148 1242 <p class=caption>Width mappings for a font family with condensed, normal
jdaggett@1148 1243 and expanded width faces
jdaggett@1148 1244 </div>
jdaggett@7377 1245
jdaggett@7377 1246 <p id=font-stretch-animation>Animation of font stretch: Font stretch is
jdaggett@7377 1247 interpolated in discrete steps. The interpolation happens as though the
jdaggett@7377 1248 ordered values are equally spaced real numbers. The interpolation result
jdaggett@7377 1249 is rounded to the nearest value, with values exactly halfway between two
jdaggett@7377 1250 values rounded towards the later value in the list above.</p>
jdaggett@512 1251 <!-- prop: font-style -->
jdaggett@512 1252
jdaggett@1662 1253 <h3 id=font-style-prop><span class=secno>3.4 </span>Font style: the <a
jdaggett@1662 1254 href="#propdef-font-style">font-style</a> property</h3>
jdaggett@1662 1255
jdaggett@4624 1256 <table class=propdef id=namefont-stylevaluenormal-italic-oblique>
jdaggett@484 1257 <tbody>
jdaggett@484 1258 <tr>
jdaggett@484 1259 <td>Name:
jdaggett@484 1260
jdaggett@8278 1261 <td><dfn id=propdef-font-style
jdaggett@8278 1262 title="font-style!!property">font-style</dfn>
jdaggett@484 1263
jdaggett@484 1264 <tr>
jdaggett@484 1265 <td>Value:
jdaggett@484 1266
jdaggett@8278 1267 <td><a href="#font-style-normal-value"
jdaggett@8278 1268 title="normal!!font-style">normal</a> | <a href="#italic">italic</a> |
jdaggett@8278 1269 <a href="#oblique">oblique</a>
jdaggett@484 1270
jdaggett@484 1271 <tr>
jdaggett@484 1272 <td>Initial:
jdaggett@484 1273
jdaggett@484 1274 <td>normal
jdaggett@484 1275
jdaggett@484 1276 <tr>
jdaggett@484 1277 <td>Applies to:
jdaggett@484 1278
jdaggett@484 1279 <td>all elements
jdaggett@484 1280
jdaggett@484 1281 <tr>
jdaggett@484 1282 <td>Inherited:
jdaggett@484 1283
jdaggett@484 1284 <td>yes
jdaggett@484 1285
jdaggett@484 1286 <tr>
jdaggett@484 1287 <td>Percentages:
jdaggett@484 1288
jdaggett@484 1289 <td>N/A
jdaggett@484 1290
jdaggett@484 1291 <tr>
jdaggett@484 1292 <td>Media:
jdaggett@484 1293
jdaggett@484 1294 <td>visual
jdaggett@484 1295
jdaggett@484 1296 <tr>
jdaggett@1148 1297 <td>Computed value:
jdaggett@484 1298
jdaggett@484 1299 <td>as specified
jdaggett@7377 1300
jdaggett@7377 1301 <tr>
jdaggett@7377 1302 <td>Animatable:
jdaggett@7377 1303
jdaggett@7377 1304 <td>no
jdaggett@484 1305 </table>
jdaggett@484 1306
jdaggett@8278 1307 <p>The <a href="#propdef-font-style" title="font-style!!property">‘<code
jdaggett@8278 1308 class=property>font-style</code>’</a> property allows italic or oblique
jdaggett@8278 1309 faces to be selected. Italic forms are generally cursive in nature while
jdaggett@8278 1310 oblique faces are typically sloped versions of the regular face. Oblique
jdaggett@8278 1311 faces can be simulated by artificially sloping the glyphs of the regular
jdaggett@8278 1312 face. Compare the artificially sloped renderings of Palatino ‘<code
jdaggett@2556 1313 class=property>a</code>’ and Baskerville ‘<code
jdaggett@1148 1314 class=property>N</code>’ in grey with the actual italic versions:
jdaggett@518 1315
jdaggett@1150 1316 <div class=figure><img alt="artificial sloping vs. real italics"
jdaggett@1150 1317 src=realvsfakeitalics.png>
jdaggett@890 1318 <p class=caption>Artificial sloping versus real italics
jdaggett@512 1319 </div>
jdaggett@518 1320
jdaggett@8278 1321 <p>Values have the following meanings:
jdaggett@8278 1322
jdaggett@8278 1323 <dl>
jdaggett@8278 1324 <dt><dfn id=font-style-normal-value
jdaggett@8278 1325 title="normal!!font-style">normal</dfn>
jdaggett@8278 1326
jdaggett@8278 1327 <dd>selects a face that is classified as a normal face, one that is
jdaggett@8278 1328 neither italic or obliqued
jdaggett@8278 1329
jdaggett@8278 1330 <dt><dfn id=italic>italic</dfn>
jdaggett@8278 1331
jdaggett@8278 1332 <dd>selects a font that is labeled as an italic face, or an oblique face
jdaggett@8278 1333 if one is not
jdaggett@8278 1334
jdaggett@8278 1335 <dt><dfn id=oblique>oblique</dfn>
jdaggett@8278 1336
jdaggett@8278 1337 <dd>selects a font that is labeled as an oblique face, or an italic face
jdaggett@8278 1338 if one is not
jdaggett@8278 1339 </dl>
jdaggett@8278 1340
jdaggett@8278 1341 <p>If no italic or oblique face is available, oblique faces can be
jdaggett@8363 1342 synthesized by rendering non-obliqued faces with an artificial obliquing
jdaggett@8363 1343 operation. The use of these artificially obliqued faces can be disabled
jdaggett@8363 1344 using the ‘<a href="#propdef-font-synthesis"><code
jdaggett@8363 1345 class=property>font-synthesis</code></a>’ property. The details of the
jdaggett@8363 1346 obliquing operation are not explicitly defined.</p>
jdaggett@8363 1347 <!-- resolution on the "undefined" nature of synthetics: http://www.w3.org/2013/06/06-css-minutes.html#item03 -->
jdaggett@518 1348
jdaggett@518 1349 <p>Many scripts lack the tradition of mixing a cursive form within text
jdaggett@518 1350 rendered with a normal face. Chinese, Japanese and Korean fonts almost
jdaggett@518 1351 always lack italic or oblique faces. Fonts that support a mixture of
jdaggett@518 1352 scripts will sometimes omit specific scripts such as Arabic from the set
jdaggett@518 1353 of glyphs supported in the italic face. User agents should be careful
jdaggett@8225 1354 about making <a href="#character-map"><em>character map</em></a>
jdaggett@8363 1355 assumptions across faces when implementing support for <a
jdaggett@8363 1356 href="#system-font-fallback"><em>system font fallback</em></a>.</p>
jdaggett@1662 1357 <!-- prop: font-size -->
jdaggett@1662 1358
jdaggett@1662 1359 <h3 id=font-size-prop><span class=secno>3.5 </span>Font size: the <a
jdaggett@1662 1360 href="#propdef-font-size">font-size</a> property</h3>
jdaggett@1662 1361
jdaggett@8225 1362 <table class=propdef id=namefont-sizevalueltabsolute-sizegt-ltre>
jdaggett@484 1363 <tbody>
jdaggett@484 1364 <tr>
jdaggett@484 1365 <td>Name:
jdaggett@484 1366
jdaggett@1662 1367 <td><dfn id=propdef-font-size>font-size</dfn>
jdaggett@484 1368
jdaggett@484 1369 <tr>
jdaggett@484 1370 <td>Value:
jdaggett@484 1371
jdaggett@8225 1372 <td><a href="#absolute-size-value"><var>&lt;absolute-size&gt;</var></a>
jdaggett@8225 1373 | <a href="#relative-size-value"><var>&lt;relative-size&gt;</var></a> |
jdaggett@8225 1374 <a href="#length-size-value"><var>&lt;length&gt;</var></a> | <a
jdaggett@8225 1375 href="#percentage-size-value"><var>&lt;percentage&gt;</var></a>
jdaggett@484 1376
jdaggett@484 1377 <tr>
jdaggett@484 1378 <td>Initial:
jdaggett@484 1379
jdaggett@484 1380 <td>medium
jdaggett@484 1381
jdaggett@484 1382 <tr>
jdaggett@484 1383 <td>Applies to:
jdaggett@484 1384
jdaggett@484 1385 <td>all elements
jdaggett@484 1386
jdaggett@484 1387 <tr>
jdaggett@484 1388 <td>Inherited:
jdaggett@484 1389
jdaggett@484 1390 <td>yes
jdaggett@484 1391
jdaggett@484 1392 <tr>
jdaggett@484 1393 <td>Percentages:
jdaggett@484 1394
jdaggett@484 1395 <td>refer to parent element's font size
jdaggett@484 1396
jdaggett@484 1397 <tr>
jdaggett@484 1398 <td>Media:
jdaggett@484 1399
jdaggett@484 1400 <td>visual
jdaggett@484 1401
jdaggett@484 1402 <tr>
jdaggett@1148 1403 <td>Computed value:
jdaggett@484 1404
jdaggett@484 1405 <td>absolute length
jdaggett@7377 1406
jdaggett@7377 1407 <tr>
jdaggett@7377 1408 <td>Animatable:
jdaggett@7377 1409
jdaggett@7377 1410 <td>as <a
jdaggett@7377 1411 href="http://dev.w3.org/csswg/css3-transitions/#animtype-length">length</a>
jdaggett@484 1412 </table>
jdaggett@484 1413
jdaggett@512 1414 <p>This property indicates the desired height of glyphs from the font. For
jdaggett@512 1415 scalable fonts, the font-size is a scale factor applied to the EM unit of
jdaggett@512 1416 the font. (Note that certain glyphs may bleed outside their EM box.) For
jdaggett@512 1417 non-scalable fonts, the font-size is converted into absolute units and
jdaggett@512 1418 matched against the declared font-size of the font, using the same
jdaggett@512 1419 absolute coordinate space for both of the matched values. Values have the
jdaggett@512 1420 following meanings:
jdaggett@512 1421
jdaggett@512 1422 <dl>
jdaggett@8225 1423 <dt><dfn id=absolute-size-value><var>&lt;absolute-size&gt;</var></dfn>
jdaggett@8225 1424
jdaggett@8225 1425 <dd> An <a
jdaggett@8225 1426 href="#absolute-size-value"><var>&lt;absolute-size&gt;</var></a> keyword
jdaggett@8225 1427 refers to an entry in a table of font sizes computed and kept by the user
jdaggett@8225 1428 agent. Possible values are:
jdaggett@512 1429 <p> [ xx-small | x-small | small | medium | large | x-large | xx-large ]</p>
jdaggett@512 1430
jdaggett@8225 1431 <dt><dfn id=relative-size-value><var>&lt;relative-size&gt;</var></dfn>
jdaggett@8225 1432
jdaggett@8225 1433 <dd> A <a href="#relative-size-value"><var>&lt;relative-size&gt;</var></a>
jdaggett@8225 1434 keyword is interpreted relative to the table of font sizes and the
jdaggett@8225 1435 computed ‘<a href="#propdef-font-size"><code
jdaggett@8225 1436 class=property>font-size</code></a>’ of the parent element. Possible
jdaggett@8225 1437 values are:
jdaggett@890 1438 <p> [ larger | smaller ]
jdaggett@890 1439
jdaggett@1148 1440 <p> For example, if the parent element has a font size of ‘<code
jdaggett@1148 1441 class=property>medium</code>’, a value of ‘<code
jdaggett@1148 1442 class=property>larger</code>’ will make the font size of the current
jdaggett@1148 1443 element be ‘<code class=property>large</code>’. If the parent
jdaggett@1148 1444 element's size is not close to a table entry, the user agent is free to
jdaggett@1148 1445 interpolate between table entries or round off to the closest one. The
jdaggett@1148 1446 user agent may have to extrapolate table values if the numerical value
jdaggett@1148 1447 goes beyond the keywords.
jdaggett@512 1448
jdaggett@8225 1449 <dt><dfn id=length-size-value><var>&lt;length&gt;</var></dfn>
jdaggett@512 1450
jdaggett@8187 1451 <dd>A length value specifies an absolute font size (independent of the
jdaggett@8187 1452 user agent's font table). Negative lengths are illegal.
jdaggett@512 1453
jdaggett@8225 1454 <dt><dfn id=percentage-size-value><var>&lt;percentage&gt;</var></dfn>
jdaggett@512 1455
jdaggett@512 1456 <dd>A percentage value specifies an absolute font size relative to the
jdaggett@512 1457 parent element's font size. Use of percentage values, or values in
jdaggett@1148 1458 ‘<code class=property>em</code>’s, leads to more robust and
jdaggett@512 1459 cascadable style sheets.
jdaggett@512 1460 </dl>
jdaggett@512 1461
jdaggett@8187 1462 <p>The following table provides user agent guidelines for the absolute-size
jdaggett@8187 1463 scaling factor and their mapping to HTML heading and absolute font-sizes.
jdaggett@8187 1464 The ‘<code class=property>medium</code>’ value is used as the
jdaggett@8187 1465 reference middle value. The user agent may fine-tune these values for
jdaggett@8187 1466 different fonts or different types of display devices.
jdaggett@1244 1467
jdaggett@1244 1468 <table class=data>
jdaggett@1152 1469 <thead>
jdaggett@1152 1470 <tr>
jdaggett@1152 1471 <th>CSS absolute-size values
jdaggett@1152 1472
jdaggett@1152 1473 <th>xx-small
jdaggett@1152 1474
jdaggett@1152 1475 <th>x-small
jdaggett@1152 1476
jdaggett@1152 1477 <th>small
jdaggett@1152 1478
jdaggett@1152 1479 <th>medium
jdaggett@1152 1480
jdaggett@1152 1481 <th>large
jdaggett@1152 1482
jdaggett@1152 1483 <th>x-large
jdaggett@1152 1484
jdaggett@1152 1485 <th>xx-large
jdaggett@1152 1486
jdaggett@1152 1487 <th> 
jdaggett@1152 1488
jdaggett@512 1489 <tbody>
jdaggett@512 1490 <tr>
jdaggett@1152 1491 <th>scaling factor
jdaggett@1152 1492
jdaggett@1152 1493 <td>3/5
jdaggett@1152 1494
jdaggett@1152 1495 <td>3/4
jdaggett@1152 1496
jdaggett@1152 1497 <td>8/9
jdaggett@1152 1498
jdaggett@1152 1499 <td>1
jdaggett@1152 1500
jdaggett@1152 1501 <td>6/5
jdaggett@1152 1502
jdaggett@1152 1503 <td>3/2
jdaggett@1152 1504
jdaggett@1152 1505 <td>2/1
jdaggett@1152 1506
jdaggett@1152 1507 <td>3/1
jdaggett@512 1508
jdaggett@512 1509 <tr>
jdaggett@8187 1510 <th>HTML headings
jdaggett@1152 1511
jdaggett@1152 1512 <td>h6
jdaggett@1152 1513
jdaggett@1152 1514 <td> 
jdaggett@1152 1515
jdaggett@1152 1516 <td>h5
jdaggett@1152 1517
jdaggett@1152 1518 <td>h4
jdaggett@1152 1519
jdaggett@1152 1520 <td>h3
jdaggett@1152 1521
jdaggett@1152 1522 <td>h2
jdaggett@1152 1523
jdaggett@1152 1524 <td>h1
jdaggett@1152 1525
jdaggett@1152 1526 <td> 
jdaggett@512 1527
jdaggett@512 1528 <tr>
jdaggett@8187 1529 <th>HTML font sizes
jdaggett@1152 1530
jdaggett@1152 1531 <td>1
jdaggett@1152 1532
jdaggett@1152 1533 <td> 
jdaggett@1152 1534
jdaggett@1152 1535 <td>2
jdaggett@1152 1536
jdaggett@1152 1537 <td>3
jdaggett@1152 1538
jdaggett@1152 1539 <td>4
jdaggett@1152 1540
jdaggett@1152 1541 <td>5
jdaggett@1152 1542
jdaggett@1152 1543 <td>6
jdaggett@1152 1544
jdaggett@1152 1545 <td>7
jdaggett@512 1546 </table>
jdaggett@512 1547
jdaggett@512 1548 <p class=note><em><strong>Note 1.</strong> To preserve readability, an UA
jdaggett@512 1549 applying these guidelines should nevertheless avoid creating font-size
jdaggett@8272 1550 resulting in less than 9 device pixels per EM unit on a computer
jdaggett@8272 1551 display.</em>
jdaggett@512 1552
jdaggett@512 1553 <p class=note><em><strong>Note 2.</strong> In CSS1, the suggested scaling
jdaggett@512 1554 factor between adjacent indexes was 1.5 which user experience proved to be
jdaggett@512 1555 too large. In CSS2, the suggested scaling factor for computer screen
jdaggett@512 1556 between adjacent indexes was 1.2 which still created issues for the small
jdaggett@512 1557 sizes. The new scaling factor varies between each index to provide a
jdaggett@512 1558 better readability.</em>
jdaggett@512 1559
jdaggett@6659 1560 <p>The actual value of this property may differ from the computed value due
jdaggett@6659 1561 a numerical value on ‘<a href="#propdef-font-size-adjust"><code
jdaggett@4624 1562 class=property>font-size-adjust</code></a>’ and the unavailability of
jdaggett@4624 1563 certain font sizes.
jdaggett@512 1564
jdaggett@512 1565 <p>Child elements inherit the computed <a class=noxref
jdaggett@6659 1566 href="#font-size-prop"> <span class=property>‘<code
jdaggett@1148 1567 class=property>font-size</code>’</span></a> value (otherwise, the effect
jdaggett@2556 1568 of <a class=noxref href="#font-size-adjust-prop"><span
jdaggett@2556 1569 class=property>‘<code
jdaggett@1148 1570 class=property>font-size-adjust</code>’</span></a> would compound).
jdaggett@512 1571
jdaggett@512 1572 <div class=example>
jdaggett@8699 1573 <p style="display:none">Example(s):</p>
jdaggett@890 1574
jdaggett@512 1575 <pre>p { font-size: 12pt; }
jdaggett@512 1576 blockquote { font-size: larger }
jdaggett@512 1577 em { font-size: 150% }
jdaggett@512 1578 em { font-size: 1.5em }
jdaggett@512 1579 </pre>
jdaggett@512 1580 </div>
jdaggett@512 1581 <!-- prop: font-size-adjust -->
jdaggett@512 1582
jdaggett@1662 1583 <h3 id=font-size-adjust-prop><span class=secno>3.6 </span>Relative sizing:
jdaggett@1662 1584 the <a href="#propdef-font-size-adjust">font-size-adjust</a> property</h3>
jdaggett@1662 1585
jdaggett@8968 1586 <table class=propdef id=namefont-size-adjustvaluenone-ltnumbergt>
jdaggett@484 1587 <tbody>
jdaggett@484 1588 <tr>
jdaggett@484 1589 <td>Name:
jdaggett@484 1590
jdaggett@1662 1591 <td><dfn id=propdef-font-size-adjust>font-size-adjust</dfn>
jdaggett@484 1592
jdaggett@484 1593 <tr>
jdaggett@484 1594 <td>Value:
jdaggett@484 1595
jdaggett@8278 1596 <td><a href="#font-size-adjust-none-value"
jdaggett@8278 1597 title="none!!font-size-adjust">none</a> | <a
jdaggett@8225 1598 href="#aspect-ratio-value"><var>&lt;number&gt;</var></a>
jdaggett@484 1599
jdaggett@484 1600 <tr>
jdaggett@484 1601 <td>Initial:
jdaggett@484 1602
jdaggett@484 1603 <td>none
jdaggett@484 1604
jdaggett@484 1605 <tr>
jdaggett@484 1606 <td>Applies to:
jdaggett@484 1607
jdaggett@484 1608 <td>all elements
jdaggett@484 1609
jdaggett@484 1610 <tr>
jdaggett@484 1611 <td>Inherited:
jdaggett@484 1612
jdaggett@484 1613 <td>yes
jdaggett@484 1614
jdaggett@484 1615 <tr>
jdaggett@484 1616 <td>Percentages:
jdaggett@484 1617
jdaggett@554 1618 <td>N/A
jdaggett@484 1619
jdaggett@484 1620 <tr>
jdaggett@484 1621 <td>Media:
jdaggett@484 1622
jdaggett@484 1623 <td>visual
jdaggett@484 1624
jdaggett@484 1625 <tr>
jdaggett@1148 1626 <td>Computed value:
jdaggett@484 1627
jdaggett@554 1628 <td>as specified
jdaggett@7377 1629
jdaggett@7377 1630 <tr>
jdaggett@7377 1631 <td>Animatable:
jdaggett@7377 1632
jdaggett@7377 1633 <td>as <a
jdaggett@7377 1634 href="http://dev.w3.org/csswg/css3-transitions/#animtype-number">number</a>
jdaggett@484 1635 </table>
jdaggett@484 1636
jdaggett@555 1637 <p>For any given font size, the apparent size and legibility of text varies
jdaggett@555 1638 across fonts. For scripts such as Latin or Cyrillic that distinguish
jdaggett@555 1639 between upper and lowercase letters, the relative height of lowercase
jdaggett@555 1640 letters compared to their uppercase counterparts is a determining factor
jdaggett@555 1641 of legibility. This is commonly referred to as the <a class=index-def
jdaggett@4624 1642 href="#aspect-value" id=aspect-value0 title="aspect value"><dfn
jdaggett@4624 1643 id=aspect-value>aspect value</dfn></a>. Precisely defined, it is equal to
jdaggett@4624 1644 the x-height of a font divided by the font size.
jdaggett@555 1645
jdaggett@555 1646 <p>In situations where font fallback occurs, fallback fonts may not share
jdaggett@555 1647 the same aspect ratio as the desired font family and will thus appear less
jdaggett@8968 1648 readable. The ‘<a href="#propdef-font-size-adjust"><code
jdaggett@8968 1649 class=property>font-size-adjust</code></a>’ property is a way to
jdaggett@8968 1650 preserve the readability of text when font fallback occurs. It does this
jdaggett@8968 1651 by adjusting the font-size so that the x-height is the same regardless of
jdaggett@8968 1652 the font used.
jdaggett@547 1653
jdaggett@547 1654 <div class=example>
jdaggett@547 1655 <p>The style defined below defines Verdana as the desired font family, but
jdaggett@547 1656 if Verdana is not available Futura or Times will be used.</p>
jdaggett@547 1657
jdaggett@8277 1658 <pre>p {
jdaggett@8277 1659 font-family: Verdana, Futura, Times;
jdaggett@547 1660 }
jdaggett@547 1661
jdaggett@547 1662 &lt;p>Lorem ipsum dolor sit amet, ...&lt;/p>
jdaggett@547 1663 </pre>
jdaggett@547 1664
jdaggett@547 1665 <p>Verdana has a relatively high aspect ratio, lowercase letters are
jdaggett@547 1666 relatively tall compared to uppercase letters, so at small sizes text
jdaggett@547 1667 appears legible. Times has a lower aspect ratio and so if fallback
jdaggett@547 1668 occurs, the text will be less legible at small sizes than Verdana.</p>
jdaggett@547 1669 </div>
jdaggett@547 1670
jdaggett@547 1671 <p>How text rendered in each of these fonts compares is shown below, the
jdaggett@547 1672 columns show text rendered in Verdana, Futura and Times. The same
jdaggett@547 1673 font-size value is used across cells within each row and red lines are
jdaggett@547 1674 included to show the differences in x-height. In the upper half each row
jdaggett@547 1675 is rendered in the same font-size value. The same is true for the lower
jdaggett@8968 1676 half but in this half the ‘<a href="#propdef-font-size-adjust"><code
jdaggett@8968 1677 class=property>font-size-adjust</code></a>’ property is also set so that
jdaggett@2462 1678 the actual font size is adjusted to preserve the x-height across each row.
jdaggett@547 1679 Note how small text remains relatively legible across each row in the
jdaggett@547 1680 lower half.
jdaggett@547 1681
jdaggett@8968 1682 <div class=figure><img alt="text with and without 'font-size-adjust'"
jdaggett@1150 1683 src=fontsizeadjust.png>
jdaggett@8968 1684 <p class=caption>Text with and without the use of ‘<a
jdaggett@8968 1685 href="#propdef-font-size-adjust"><code
jdaggett@8968 1686 class=property>font-size-adjust</code></a>’
jdaggett@547 1687 </div>
jdaggett@512 1688
jdaggett@8640 1689 <p>This property allows authors to specify an <a
jdaggett@8640 1690 href="#aspect-value"><i>aspect value</i></a> for an element that will
jdaggett@8640 1691 effectively preserve the x-height of the first choice font, whether it is
jdaggett@8640 1692 substituted or not. Values have the following meanings:
jdaggett@512 1693
jdaggett@512 1694 <dl>
jdaggett@8278 1695 <dt><dfn id=font-size-adjust-none-value
jdaggett@8278 1696 title="none!!font-size-adjust">none</dfn>
jdaggett@512 1697
jdaggett@512 1698 <dd>Do not preserve the font's x-height.
jdaggett@512 1699
jdaggett@8225 1700 <dt><dfn id=aspect-ratio-value><var>&lt;number&gt;</var></dfn>
jdaggett@512 1701
jdaggett@8640 1702 <dd>Specifies the <a href="#aspect-value"><i>aspect value</i></a> used in
jdaggett@8640 1703 the calculation below to calculate the adjusted font size:
jdaggett@8277 1704 <pre>c = ( a / a' ) s
jdaggett@512 1705 </pre>
jdaggett@512 1706
jdaggett@512 1707 <p>where:</p>
jdaggett@512 1708
jdaggett@554 1709 <pre>s = font-size value
jdaggett@8968 1710 a = <a href="#aspect-value"><i>aspect value</i></a> as specified by the 'font-size-adjust' property
jdaggett@8640 1711 a' = <a href="#aspect-value"><i>aspect value</i></a> of actual font
jdaggett@554 1712 c = adjusted font-size to use
jdaggett@512 1713 </pre>
jdaggett@554 1714
jdaggett@554 1715 <p>This value applies to any font that is selected but in typical usage
jdaggett@8640 1716 it should be based on the <a href="#aspect-value"><i>aspect
jdaggett@8640 1717 value</i></a> of the first font in the font-family list. If this is
jdaggett@8640 1718 specified accurately, the <tt>(a/a')</tt> term in the formula above is
jdaggett@8640 1719 effectively 1 for the first font and no adjustment occurs. If the value
jdaggett@8640 1720 is specified inaccurately, text rendered using the first font in the
jdaggett@8640 1721 family list will display differently in older user agents that don't
jdaggett@8968 1722 support ‘<a href="#propdef-font-size-adjust"><code
jdaggett@8968 1723 class=property>font-size-adjust</code></a>’.</p>
jdaggett@512 1724 </dl>
jdaggett@512 1725
jdaggett@8640 1726 <p>The value of ‘<a href="#propdef-font-size-adjust"><code
jdaggett@8968 1727 class=property>font-size-adjust</code></a>’ affects the used value of
jdaggett@8968 1728 ‘<a href="#propdef-font-size"><code
jdaggett@8968 1729 class=property>font-size</code></a>’ but does not affect the computed
jdaggett@8968 1730 value. It affects the size of relative units that are based on font
jdaggett@8968 1731 metrics of the <a href="#first-available-font"><i>first available
jdaggett@8968 1732 font</i></a> such as <code>ex</code> and <code>ch</code> but does not
jdaggett@8968 1733 affect the size of <code>em</code> units. Since numeric values of <a
jdaggett@8957 1734 href="http://www.w3.org/TR/CSS2/visudet.html#propdef-line-height">‘<code
jdaggett@8968 1735 class=property>line-height</code>’</a> refer to the computed size of
jdaggett@8968 1736 ‘<a href="#propdef-font-size"><code
jdaggett@8968 1737 class=property>font-size</code></a>’, ‘<a
jdaggett@8968 1738 href="#propdef-font-size-adjust"><code
jdaggett@8968 1739 class=property>font-size-adjust</code></a>’ does not affect the used
jdaggett@8968 1740 value of <a
jdaggett@8957 1741 href="http://www.w3.org/TR/CSS2/visudet.html#propdef-line-height">‘<code
jdaggett@8968 1742 class=property>line-height</code>’</a>.
jdaggett@8968 1743
jdaggett@8968 1744 <p class=note>In CSS, authors often specify <a
jdaggett@8968 1745 href="http://www.w3.org/TR/CSS2/visudet.html#propdef-line-height">‘<code
jdaggett@8968 1746 class=property>line-height</code>’</a> as a multiple of the ‘<a
jdaggett@8968 1747 href="#propdef-font-size"><code class=property>font-size</code></a>’.
jdaggett@8968 1748 Since the ‘<a href="#propdef-font-size-adjust"><code
jdaggett@8968 1749 class=property>font-size-adjust</code></a>’ property affects the used
jdaggett@8968 1750 value of ‘<a href="#propdef-font-size"><code
jdaggett@8968 1751 class=property>font-size</code></a>’, authors should take care setting
jdaggett@8968 1752 the line height when ‘<a href="#propdef-font-size-adjust"><code
jdaggett@8957 1753 class=property>font-size-adjust</code></a>’ is used. Setting the line
jdaggett@8968 1754 height too tightly can result in overlapping lines of text in this
jdaggett@8957 1755 situation.
jdaggett@8957 1756
jdaggett@8640 1757 <p>Authors can calculate the <a href="#aspect-value"><i>aspect
jdaggett@8640 1758 value</i></a> for a given font by comparing spans with the same content
jdaggett@8968 1759 but different ‘<a href="#propdef-font-size-adjust"><code
jdaggett@8968 1760 class=property>font-size-adjust</code></a>’ properties. If the same
jdaggett@8968 1761 font-size is used, the spans will match when the ‘<a
jdaggett@8968 1762 href="#propdef-font-size-adjust"><code
jdaggett@8968 1763 class=property>font-size-adjust</code></a>’ value is accurate for the
jdaggett@8640 1764 given font.
jdaggett@554 1765
jdaggett@554 1766 <div class=example>
jdaggett@8640 1767 <p>Two spans with borders are used to determine the <a
jdaggett@8968 1768 href="#aspect-value"><i>aspect value</i></a> of a font. The ‘<a
jdaggett@8968 1769 href="#propdef-font-size"><code class=property>font-size</code></a>’ is
jdaggett@8968 1770 the same for both spans but the ‘<a
jdaggett@8968 1771 href="#propdef-font-size-adjust"><code
jdaggett@8968 1772 class=property>font-size-adjust</code></a>’ property is specified only
jdaggett@8968 1773 for the right span. Starting with a value of 0.5, the aspect value can be
jdaggett@8968 1774 adjusted until the borders around the two letters line up.</p>
jdaggett@554 1775
jdaggett@554 1776 <pre>p {
jdaggett@554 1777 font-family: Futura;
jdaggett@554 1778 font-size: 500px;
jdaggett@554 1779 }
jdaggett@554 1780
jdaggett@554 1781 span {
jdaggett@554 1782 border: solid 1px red;
jdaggett@554 1783 }
jdaggett@554 1784
jdaggett@554 1785 .adjust {
jdaggett@554 1786 font-size-adjust: 0.5;
jdaggett@554 1787 }
jdaggett@554 1788
jdaggett@554 1789 &lt;p>&lt;span>b&lt;/span>&lt;span class="adjust">b&lt;/span>&lt;/p>
jdaggett@554 1790 </pre>
jdaggett@554 1791
jdaggett@8640 1792 <div class=figure><img alt="Futura with an <i>aspect value</i> of 0.5"
jdaggett@1150 1793 src=beforefontsizeadjust.png>
jdaggett@8640 1794 <p class=caption>Futura with an <a href="#aspect-value"><i>aspect
jdaggett@8640 1795 value</i></a> of 0.5
jdaggett@554 1796 </div>
jdaggett@554 1797
jdaggett@554 1798 <p>The box on the right is a bit bigger than the one on the left, so the
jdaggett@8640 1799 <a href="#aspect-value"><i>aspect value</i></a> of this font is something
jdaggett@8640 1800 less than 0.5. Adjust the value until the boxes align.</p>
jdaggett@554 1801 </div>
jdaggett@512 1802 <!-- prop: font -->
jdaggett@512 1803
jdaggett@1662 1804 <h3 id=font-prop><span class=secno>3.7 </span>Shorthand font property: the
jdaggett@1662 1805 <a href="#propdef-font">font</a> property</h3>
jdaggett@1662 1806
jdaggett@8225 1807 <table class=propdef id=namefontvalue-ltlsquofont-stylersquogt-l>
jdaggett@484 1808 <tbody>
jdaggett@484 1809 <tr>
jdaggett@484 1810 <td>Name:
jdaggett@484 1811
jdaggett@1662 1812 <td><dfn id=propdef-font>font</dfn>
jdaggett@484 1813
jdaggett@484 1814 <tr>
jdaggett@484 1815 <td>Value:
jdaggett@484 1816
jdaggett@8278 1817 <td>[ [ <var>&lt;<a href="#propdef-font-style"
jdaggett@8278 1818 title="font-style!!property">‘<code
jdaggett@8278 1819 class=property>font-style</code>’</a>&gt;</var> || <a
jdaggett@8225 1820 href="#font-variant-css21-values"><var>&lt;font-variant-css21&gt;</var></a>
jdaggett@8278 1821 || <var>&lt;<a href="#propdef-font-weight"
jdaggett@8278 1822 title="font-weight!!property">‘<code
jdaggett@8278 1823 class=property>font-weight</code>’</a>&gt;</var> || <var>&lt;<a
jdaggett@8278 1824 href="#propdef-font-stretch" title="font-stretch!!property">‘<code
jdaggett@8278 1825 class=property>font-stretch</code>’</a></var> ]? <var>&lt;‘<a
jdaggett@8225 1826 href="#propdef-font-size"><code
jdaggett@8225 1827 class=property>font-size</code></a>’&gt;</var> [ / <var>&lt;‘<code
jdaggett@8278 1828 class=property>line-height</code>’&gt;</var> ]? <var>&lt;<a
jdaggett@8278 1829 href="#propdef-font-family" title="font-family!!property">‘<code
jdaggett@8278 1830 class=property>font-family</code>’</a>&gt;</var> ] | caption | icon |
jdaggett@8225 1831 menu | message-box | small-caption | status-bar
jdaggett@484 1832
jdaggett@484 1833 <tr>
jdaggett@484 1834 <td>Initial:
jdaggett@484 1835
jdaggett@484 1836 <td>see individual properties
jdaggett@484 1837
jdaggett@484 1838 <tr>
jdaggett@484 1839 <td>Applies to:
jdaggett@484 1840
jdaggett@484 1841 <td>all elements
jdaggett@484 1842
jdaggett@484 1843 <tr>
jdaggett@484 1844 <td>Inherited:
jdaggett@484 1845
jdaggett@484 1846 <td>yes
jdaggett@484 1847
jdaggett@484 1848 <tr>
jdaggett@484 1849 <td>Percentages:
jdaggett@484 1850
jdaggett@484 1851 <td>see individual properties
jdaggett@484 1852
jdaggett@484 1853 <tr>
jdaggett@484 1854 <td>Media:
jdaggett@484 1855
jdaggett@484 1856 <td>visual
jdaggett@484 1857
jdaggett@484 1858 <tr>
jdaggett@1148 1859 <td>Computed value:
jdaggett@484 1860
jdaggett@484 1861 <td>see individual properties
jdaggett@7377 1862
jdaggett@7377 1863 <tr>
jdaggett@7377 1864 <td>Animatable:
jdaggett@7377 1865
jdaggett@7377 1866 <td>see individual properties
jdaggett@484 1867 </table>
jdaggett@1732 1868
jdaggett@4624 1869 <p>The <span class=property>‘<a href="#propdef-font"><code
jdaggett@4624 1870 class=property>font</code></a>’</span> property is, except as described
jdaggett@8278 1871 below, a shorthand property for setting <a href="#propdef-font-style"
jdaggett@8278 1872 title="font-style!!property">‘<code
jdaggett@8278 1873 class=property>font-style</code>’</a>, <a href="#propdef-font-variant"
jdaggett@8278 1874 title="font-variant!!property">‘<code
jdaggett@8278 1875 class=property>font-variant</code>’</a>, <a href="#propdef-font-weight"
jdaggett@8278 1876 title="font-weight!!property">‘<code
jdaggett@8278 1877 class=property>font-weight</code>’</a>, <a href="#propdef-font-stretch"
jdaggett@8278 1878 title="font-stretch!!property">‘<code
jdaggett@8278 1879 class=property>font-stretch</code>’</a>, <span class=property>‘<a
jdaggett@8278 1880 href="#propdef-font-size"><code
jdaggett@8278 1881 class=property>font-size</code></a>’</span>, <a class=property
jdaggett@8278 1882 href="http://www.w3.org/TR/CSS2/visudet.html#propdef-line-height">‘<code
jdaggett@8278 1883 class=property>line-height</code>’</a>, <a href="#propdef-font-family"
jdaggett@8278 1884 title="font-family!!property">‘<code
jdaggett@8278 1885 class=property>font-family</code>’</a> at the same place in the
jdaggett@8278 1886 stylesheet. Values for the <a href="#propdef-font-variant"
jdaggett@8278 1887 title="font-variant!!property">‘<code
jdaggett@8278 1888 class=property>font-variant</code>’</a> property may also be included
jdaggett@8313 1889 but only those supported in CSS 2.1, none of the <a
jdaggett@8313 1890 href="#propdef-font-variant" title="font-variant!!property">‘<code
jdaggett@8313 1891 class=property>font-variant</code>’</a> values added in this
jdaggett@8313 1892 specification can be used in the <span class=property>‘<a
jdaggett@8278 1893 href="#propdef-font"><code class=property>font</code></a>’</span>
jdaggett@8278 1894 shorthand:
jdaggett@1732 1895
jdaggett@1732 1896 <pre
jdaggett@8225 1897 class=prod><dfn id=font-variant-css21-values><var>&lt;font-variant-css21&gt;</var></dfn> = [normal | small-caps]</pre>
jdaggett@1732 1898
jdaggett@1732 1899 <p>The syntax of this property is based on a traditional typographical
jdaggett@1732 1900 shorthand notation to set multiple properties related to fonts.
jdaggett@512 1901
jdaggett@8197 1902 <p>All subproperties of the ‘<a href="#propdef-font"><code
jdaggett@8197 1903 class=property>font</code></a>’ property are first reset to their
jdaggett@8197 1904 initial values, including those listed above plus <span
jdaggett@4624 1905 class=property>‘<a href="#propdef-font-size-adjust"><code
jdaggett@4624 1906 class=property>font-size-adjust</code></a>’</span>, <span
jdaggett@4624 1907 class=property>‘<a href="#propdef-font-kerning"><code
jdaggett@8278 1908 class=property>font-kerning</code></a>’</span>, subproperties of <a
jdaggett@8278 1909 href="#propdef-font-variant" title="font-variant!!property">‘<code
jdaggett@8278 1910 class=property>font-variant</code>’</a> and and <span>‘<a
jdaggett@8278 1911 href="#propdef-font-language-override"><code
jdaggett@8197 1912 class=property>font-language-override</code></a>’</span>. Then, those
jdaggett@8197 1913 properties that are given explicit values in the <span
jdaggett@8197 1914 class=property>‘<a href="#propdef-font"><code
jdaggett@4624 1915 class=property>font</code></a>’</span> shorthand are set to those
jdaggett@512 1916 values. For a definition of allowed and initial values, see the previously
jdaggett@512 1917 defined properties. For reasons of backwards compatibility, it is not
jdaggett@4624 1918 possible to set <span class=property>‘<a
jdaggett@7020 1919 href="#propdef-font-size-adjust"><code
jdaggett@7020 1920 class=property>font-size-adjust</code></a>’</span> to anything other
jdaggett@7020 1921 than its initial value using the <span class=property>‘<a
jdaggett@4624 1922 href="#propdef-font"><code class=property>font</code></a>’</span>
jdaggett@7020 1923 shorthand property; instead, use the individual property.
jdaggett@512 1924
jdaggett@512 1925 <div class=example>
jdaggett@8699 1926 <p style="display:none">Example(s):</p>
jdaggett@890 1927
jdaggett@512 1928 <pre>p { font: 12pt/14pt sans-serif }
jdaggett@512 1929 p { font: 80% sans-serif }
jdaggett@512 1930 p { font: x-large/110% &quot;new century schoolbook&quot;, serif }
jdaggett@512 1931 p { font: bold italic large Palatino, serif }
jdaggett@512 1932 p { font: normal small-caps 120%/120% fantasy }
jdaggett@7020 1933 p { font: condensed oblique 12pt &quot;Helvetica Neue&quot;, serif; }
jdaggett@512 1934 </pre>
jdaggett@512 1935
jdaggett@1148 1936 <p> In the second rule, the font size percentage value (‘<code
jdaggett@8187 1937 class=css>80%</code>’) refers to the computed ‘<a
jdaggett@8187 1938 href="#propdef-font-size"><code class=property>font-size</code></a>’ of
jdaggett@8187 1939 the parent element. In the third rule, the line height percentage
jdaggett@8187 1940 (‘<code class=css>110%</code>’) refers to the font size of the
jdaggett@8187 1941 element itself.
jdaggett@512 1942
jdaggett@8278 1943 <p>The first three rules do not specify the <a
jdaggett@8278 1944 href="#propdef-font-variant" title="font-variant!!property">‘<code
jdaggett@8278 1945 class=property>font-variant</code>’</a> and <a
jdaggett@8278 1946 href="#propdef-font-weight" title="font-weight!!property">‘<code
jdaggett@8278 1947 class=property>font-weight</code>’</a> explicitly, so these properties
jdaggett@8368 1948 receive their initial values (<span title="normal value">‘<code
jdaggett@8368 1949 class=property>normal</code>’</span>). Notice that the font family name
jdaggett@8279 1950 "new century schoolbook", which contains spaces, is enclosed in quotes.
jdaggett@8279 1951 The fourth rule sets the <a href="#propdef-font-weight"
jdaggett@8279 1952 title="font-weight!!property">‘<code
jdaggett@8278 1953 class=property>font-weight</code>’</a> to ‘<a href="#bold"><code
jdaggett@8278 1954 class=property>bold</code></a>’, the <a href="#propdef-font-style"
jdaggett@8278 1955 title="font-style!!property">‘<code
jdaggett@8278 1956 class=property>font-style</code>’</a> to ‘<a href="#italic"><code
jdaggett@8278 1957 class=property>italic</code></a>’, and implicitly sets <a
jdaggett@8278 1958 href="#propdef-font-variant" title="font-variant!!property">‘<code
jdaggett@8368 1959 class=property>font-variant</code>’</a> to <a
jdaggett@8368 1960 href="#font-variant-normal-value" title="normal!!font-variant">‘<code
jdaggett@8368 1961 class=property>normal</code>’</a>.
jdaggett@8278 1962
jdaggett@8278 1963 <p> The fifth rule sets the <a href="#propdef-font-variant"
jdaggett@8278 1964 title="font-variant!!property">‘<code
jdaggett@8278 1965 class=property>font-variant</code>’</a> (‘<a href="#small-caps"><code
jdaggett@8278 1966 class=property>small-caps</code></a>’), the <span class=property>‘<a
jdaggett@8278 1967 href="#propdef-font-size"><code
jdaggett@4624 1968 class=property>font-size</code></a>’</span> (120% of the parent's font
jdaggett@8278 1969 size), the <a class=property
jdaggett@8278 1970 href="http://www.w3.org/TR/CSS2/visudet.html#propdef-line-height">‘<code
jdaggett@8278 1971 class=property>line-height</code>’</a> (120% of the font size) and the
jdaggett@8278 1972 <a href="#propdef-font-family" title="font-family!!property">‘<code
jdaggett@8278 1973 class=property>font-family</code>’</a> (‘<a href="#fantasy"><code
jdaggett@8368 1974 class=property>fantasy</code></a>’). It follows that the keyword <span
jdaggett@8368 1975 title="normal value">‘<code class=property>normal</code>’</span>
jdaggett@8368 1976 applies to the two remaining properties: <a href="#propdef-font-style"
jdaggett@8278 1977 title="font-style!!property">‘<code
jdaggett@8278 1978 class=property>font-style</code>’</a> and <a
jdaggett@8278 1979 href="#propdef-font-weight" title="font-weight!!property">‘<code
jdaggett@8278 1980 class=property>font-weight</code>’</a>.
jdaggett@8278 1981
jdaggett@8278 1982 <p>The sixth rule sets the <a href="#propdef-font-style"
jdaggett@8278 1983 title="font-style!!property">‘<code
jdaggett@8278 1984 class=property>font-style</code>’</a>, <a href="#propdef-font-stretch"
jdaggett@8278 1985 title="font-stretch!!property">‘<code
jdaggett@8278 1986 class=property>font-stretch</code>’</a>, <span class=property>‘<a
jdaggett@8278 1987 href="#propdef-font-size"><code
jdaggett@8278 1988 class=property>font-size</code></a>’</span>, and <a
jdaggett@8278 1989 href="#propdef-font-family" title="font-family!!property">‘<code
jdaggett@8278 1990 class=property>font-family</code>’</a>, the other font properties being
jdaggett@8278 1991 set to their initial values.
jdaggett@512 1992 </div>
jdaggett@512 1993
jdaggett@8278 1994 <p>Since the <a href="#propdef-font-stretch"
jdaggett@8278 1995 title="font-stretch!!property">‘<code
jdaggett@8278 1996 class=property>font-stretch</code>’</a> property was not defined in CSS
jdaggett@8278 1997 2.1, when using <a href="#propdef-font-stretch"
jdaggett@8278 1998 title="font-stretch!!property">‘<code
jdaggett@8278 1999 class=property>font-stretch</code>’</a> values within ‘<a
jdaggett@7020 2000 href="#propdef-font"><code class=property>font</code></a>’ rules,
jdaggett@7020 2001 authors should include a extra version compatible with older user agents:
jdaggett@7020 2002
jdaggett@7020 2003 <pre>p {
jdaggett@7020 2004 font: 80% sans-serif; /* for older user agents */
jdaggett@7020 2005 font: condensed 80% sans-serif;
jdaggett@7020 2006 }</pre>
jdaggett@7020 2007
jdaggett@1662 2008 <p>The following values refer to system fonts:
jdaggett@512 2009
jdaggett@512 2010 <dl>
jdaggett@512 2011 <dt><strong>caption</strong>
jdaggett@512 2012
jdaggett@512 2013 <dd>The font used for captioned controls (e.g., buttons, drop-downs,
jdaggett@512 2014 etc.).
jdaggett@512 2015
jdaggett@512 2016 <dt><strong>icon</strong>
jdaggett@512 2017
jdaggett@512 2018 <dd>The font used to label icons.
jdaggett@512 2019
jdaggett@512 2020 <dt><strong>menu</strong>
jdaggett@512 2021
jdaggett@512 2022 <dd>The font used in menus (e.g., dropdown menus and menu lists).
jdaggett@512 2023
jdaggett@512 2024 <dt><strong>message-box</strong>
jdaggett@512 2025
jdaggett@512 2026 <dd>The font used in dialog boxes.
jdaggett@512 2027
jdaggett@512 2028 <dt><strong>small-caption</strong>
jdaggett@512 2029
jdaggett@512 2030 <dd>The font used for labeling small controls.
jdaggett@512 2031
jdaggett@512 2032 <dt><strong>status-bar</strong>
jdaggett@512 2033
jdaggett@512 2034 <dd>The font used in window status bars.
jdaggett@512 2035 </dl>
jdaggett@512 2036
jdaggett@512 2037 <p>System fonts may only be set as a whole; that is, the font family, size,
jdaggett@1662 2038 weight, style, etc. are all set at the same time. These values may then be
jdaggett@512 2039 altered individually if desired. If no font with the indicated
jdaggett@512 2040 characteristics exists on a given platform, the user agent should either
jdaggett@1148 2041 intelligently substitute (e.g., a smaller version of the ‘<code
jdaggett@1148 2042 class=property>caption</code>’ font might be used for the ‘<code
jdaggett@7242 2043 class=property>small-caption</code>’ font), or substitute a user agent
jdaggett@1148 2044 default font. As for regular fonts, if, for a system font, any of the
jdaggett@1148 2045 individual properties are not part of the operating system's available
jdaggett@1148 2046 user preferences, those properties should be set to their initial values.
jdaggett@512 2047
jdaggett@1662 2048 <p>That is why this property is "almost" a shorthand property: system fonts
jdaggett@8278 2049 can only be specified with this property, not with <a
jdaggett@8278 2050 href="#propdef-font-family" title="font-family!!property">‘<code
jdaggett@8278 2051 class=property>font-family</code>’</a> itself, so <span
jdaggett@4624 2052 class=property>‘<a href="#propdef-font"><code
jdaggett@4624 2053 class=property>font</code></a>’</span> allows authors to do more than
jdaggett@4624 2054 the sum of its subproperties. However, the individual properties such as
jdaggett@8278 2055 <a href="#propdef-font-weight" title="font-weight!!property">‘<code
jdaggett@8278 2056 class=property>font-weight</code>’</a> are still given values taken from
jdaggett@8278 2057 the system font, which can be independently varied.
jdaggett@512 2058
jdaggett@7235 2059 <p>Note that the keywords used for the system fonts listed above are only
jdaggett@7235 2060 treated as keywords when they occur in the initial position, in other
jdaggett@7235 2061 positions the same string is treated as part of the font family name:
jdaggett@7235 2062
jdaggett@7235 2063 <pre> font: menu; /* use the font settings for system menus */
jdaggett@7235 2064 font: large menu; /* use a font family named "menu" */</pre>
jdaggett@7235 2065
jdaggett@512 2066 <div class=example>
jdaggett@8699 2067 <p style="display:none">Example(s):</p>
jdaggett@890 2068
jdaggett@512 2069 <pre>button { font: 300 italic 1.3em/1.7em &quot;FB Armada&quot;, sans-serif }
jdaggett@512 2070 button p { font: menu }
jdaggett@512 2071 button p em { font-weight: bolder }
jdaggett@512 2072 </pre>
jdaggett@512 2073
jdaggett@512 2074 <p>If the font used for dropdown menus on a particular system happened to
jdaggett@512 2075 be, for example, 9-point Charcoal, with a weight of 600, then P elements
jdaggett@512 2076 that were descendants of BUTTON would be displayed as if this rule were
jdaggett@890 2077 in effect:
jdaggett@512 2078
jdaggett@512 2079 <pre>button p { font: 600 9pt Charcoal }
jdaggett@512 2080 </pre>
jdaggett@512 2081
jdaggett@4624 2082 <p>Because the <span class=property>‘<a href="#propdef-font"><code
jdaggett@4624 2083 class=property>font</code></a>’</span> shorthand resets to its initial
jdaggett@4624 2084 value any property not explicitly given a value, this has the same effect
jdaggett@4624 2085 as this declaration:
jdaggett@512 2086
jdaggett@512 2087 <pre>button p {
jdaggett@512 2088 font-style: normal;
jdaggett@512 2089 font-variant: normal;
jdaggett@512 2090 font-weight: 600;
jdaggett@512 2091 font-size: 9pt;
jdaggett@512 2092 line-height: normal;
jdaggett@512 2093 font-family: Charcoal
jdaggett@8277 2094 }
jdaggett@512 2095 </pre>
jdaggett@512 2096 </div>
jdaggett@2487 2097 <!-- prop: font-synthesis -->
jdaggett@2487 2098
jdaggett@2487 2099 <h3 id=font-synthesis-prop><span class=secno>3.8 </span>Controlling
jdaggett@2487 2100 synthetic faces: the <a href="#propdef-font-synthesis">font-synthesis</a>
jdaggett@2487 2101 property</h3>
jdaggett@2487 2102
jdaggett@4624 2103 <table class=propdef id=namefont-synthesisvaluenone-weight-style>
jdaggett@2457 2104 <tbody>
jdaggett@2457 2105 <tr>
jdaggett@2457 2106 <td>Name:
jdaggett@2457 2107
jdaggett@2487 2108 <td><dfn id=propdef-font-synthesis>font-synthesis</dfn>
jdaggett@2457 2109
jdaggett@2457 2110 <tr>
jdaggett@2457 2111 <td>Value:
jdaggett@2457 2112
jdaggett@2487 2113 <td>none | [ weight || style ]
jdaggett@2457 2114
jdaggett@2457 2115 <tr>
jdaggett@2457 2116 <td>Initial:
jdaggett@2457 2117
jdaggett@2487 2118 <td>weight style
jdaggett@2457 2119
jdaggett@2457 2120 <tr>
jdaggett@2457 2121 <td>Applies to:
jdaggett@2457 2122
jdaggett@2457 2123 <td>all elements
jdaggett@2457 2124
jdaggett@2457 2125 <tr>
jdaggett@2457 2126 <td>Inherited:
jdaggett@2457 2127
jdaggett@2457 2128 <td>yes
jdaggett@2457 2129
jdaggett@2457 2130 <tr>
jdaggett@2457 2131 <td>Percentages:
jdaggett@2457 2132
jdaggett@2457 2133 <td>N/A
jdaggett@2457 2134
jdaggett@2457 2135 <tr>
jdaggett@2457 2136 <td>Media:
jdaggett@2457 2137
jdaggett@2457 2138 <td>visual
jdaggett@2457 2139
jdaggett@2457 2140 <tr>
jdaggett@2457 2141 <td>Computed value:
jdaggett@2457 2142
jdaggett@2457 2143 <td>as specified
jdaggett@7377 2144
jdaggett@7377 2145 <tr>
jdaggett@7377 2146 <td>Animatable:
jdaggett@7377 2147
jdaggett@7377 2148 <td>no
jdaggett@2457 2149 </table>
jdaggett@2457 2150
jdaggett@2487 2151 <p>This property controls whether user agents are allowed to synthesize
jdaggett@2487 2152 bold or oblique font faces when a font family lacks bold or italic faces.
jdaggett@7311 2153 If ‘<a href="#weight"><code class=property>weight</code></a>’ is not
jdaggett@7311 2154 specified, user agents must not synthesize bold faces and if ‘<code
jdaggett@2487 2155 class=property>style</code>’ is not specified user agents must not
jdaggett@8278 2156 synthesize italic faces. A value of ‘<code class=property>none</code>’
jdaggett@8278 2157 disallows all synthetic faces.
jdaggett@2457 2158
jdaggett@2457 2159 <div class=example>
jdaggett@2488 2160 <p>The style rule below disables the use of synthetically obliqued Arabic:</p>
jdaggett@2457 2161
jdaggett@2487 2162 <pre>*:lang(ar) { font-synthesis: none; }
jdaggett@2457 2163 </pre>
jdaggett@2457 2164 </div>
jdaggett@512 2165
jdaggett@6699 2166 <h2 id=font-resources><span class=secno>4 </span>Font Resources</h2>
jdaggett@545 2167
jdaggett@8311 2168 <h3 id=font-face-rule><span class=secno>4.1 </span>The <dfn
jdaggett@8311 2169 id=at-font-face-rule style="font-weight: inherit; font-style:
jdaggett@8311 2170 inherit"><code>@font-face</code></dfn> rule</h3>
jdaggett@8311 2171
jdaggett@8311 2172 <p>The <a href="#at-font-face-rule"><code>@font-face</code></a> rule allows
jdaggett@8311 2173 for linking to fonts that are automatically fetched and activated when
jdaggett@8311 2174 needed. This allows authors to select a font that closely matches the
jdaggett@8311 2175 design goals for a given page rather than limiting the font choice to a
jdaggett@8311 2176 set of fonts available on all platforms. A set of font descriptors define
jdaggett@8311 2177 the location of a font resource, either locally or externally, along with
jdaggett@8311 2178 the style characteristics of an individual face. Multiple <a
jdaggett@8311 2179 href="#at-font-face-rule"><code>@font-face</code></a> rules can be used to
jdaggett@8311 2180 construct font families with a variety of faces. Using CSS font matching
jdaggett@8311 2181 rules, a user agent can selectively download only those faces that are
jdaggett@8311 2182 needed for a given piece of text.
jdaggett@8311 2183
jdaggett@8311 2184 <p>The <a href="#at-font-face-rule"><code>@font-face</code></a> rule
jdaggett@8311 2185 consists of the <a href="#at-font-face-rule"><code>@font-face</code></a>
jdaggett@8311 2186 at-keyword followed by a block of descriptor declarations. In terms of the
jdaggett@8311 2187 grammar, this specification defines the following productions:
jdaggett@8031 2188
jdaggett@8031 2189 <pre><dfn id=fontfacerule>font_face_rule</dfn>
jdaggett@8225 2190 : <a href="#fontfacesym"><i>FONT_FACE_SYM</i></a> <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* '{' <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* <a href="#descriptordeclaration"><i>descriptor_declaration</i></a>? [ ';' <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* <a href="#descriptordeclaration"><i>descriptor_declaration</i></a>? ]* '}' <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>*
jdaggett@8031 2191 ;
jdaggett@8031 2192
jdaggett@8031 2193 <dfn id=descriptordeclaration>descriptor_declaration</dfn>
jdaggett@8225 2194 : <a href="http://www.w3.org/TR/CSS21/grammar.html#grammar"><i>property</i></a> ':' <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* <a href="http://www.w3.org/TR/CSS21/grammar.html#grammar"><i>expr</i></a>
jdaggett@8031 2195 ;</pre>
jdaggett@8031 2196
jdaggett@8032 2197 <p>The following new definitions are introduced:
jdaggett@8032 2198
jdaggett@8032 2199 <pre>- -|\\0{0,4}2d(\r\n|[ \t\r\n\f])?
jdaggett@8032 2200 F f|\\0{0,4}(46|66)(\r\n|[ \t\r\n\f])?</pre>
jdaggett@8032 2201
jdaggett@8032 2202 <p>The following new token is introduced:
jdaggett@8032 2203
jdaggett@8225 2204 <pre>@{F}{O}{N}{T}{-}{F}{A}{C}{E} {return <dfn id=fontfacesym>FONT_FACE_SYM</dfn>;}</pre>
jdaggett@8032 2205
jdaggett@8311 2206 <p>Each <a href="#at-font-face-rule"><code>@font-face</code></a> rule
jdaggett@8311 2207 specifies a value for every font descriptor, either implicitly or
jdaggett@8311 2208 explicitly. Those not given explicit values in the rule take the initial
jdaggett@8311 2209 value listed with each descriptor in this specification. These descriptors
jdaggett@8311 2210 apply solely within the context of the <a
jdaggett@8311 2211 href="#at-font-face-rule"><code>@font-face</code></a> rule in which they
jdaggett@8311 2212 are defined, and do not apply to document language elements. There is no
jdaggett@8311 2213 notion of which elements the descriptors apply to or whether the values
jdaggett@8311 2214 are inherited by child elements. When a given descriptor occurs multiple
jdaggett@8311 2215 times in a given <a href="#at-font-face-rule"><code>@font-face</code></a>
jdaggett@8311 2216 rule, only the last descriptor declaration is used and all prior
jdaggett@8311 2217 declarations for that descriptor are ignored.
jdaggett@512 2218
jdaggett@525 2219 <div class=example>
jdaggett@525 2220 <p>To use a downloadable font called Gentium:</p>
jdaggett@512 2221
jdaggett@512 2222 <pre>
jdaggett@525 2223 @font-face {
jdaggett@525 2224 font-family: Gentium;
jdaggett@8860 2225 src: url(http://example.com/fonts/Gentium.woff);
jdaggett@525 2226 }
jdaggett@525 2227
jdaggett@525 2228 p { font-family: Gentium, serif; }
jdaggett@512 2229 </pre>
jdaggett@512 2230
jdaggett@573 2231 <p>The user agent will download Gentium and use it when rendering text
jdaggett@573 2232 within paragraph elements. If for some reason the site serving the font
jdaggett@573 2233 is unavailable, the default serif font will be used.</p>
jdaggett@512 2234 </div>
jdaggett@512 2235
jdaggett@8311 2236 <p>A given set of <a href="#at-font-face-rule"><code>@font-face</code></a>
jdaggett@8311 2237 rules define a set of fonts available for use within the documents that
jdaggett@8311 2238 contain these rules. When font matching is done, fonts defined using these
jdaggett@8311 2239 rules are considered before other available fonts on a system.
jdaggett@8198 2240
jdaggett@8198 2241 <p>Downloaded fonts are only available to documents that reference them.
jdaggett@8198 2242 The process of activating these fonts must not make them available to
jdaggett@2472 2243 other applications or to documents that don't directly link to the same
jdaggett@2556 2244 font. User agent implementers might consider it convenient to use
jdaggett@2472 2245 downloaded fonts when rendering characters in other documents for which no
jdaggett@8363 2246 other available font exists as part of the <a
jdaggett@8363 2247 href="#system-font-fallback"><em>system font fallback</em></a> procedure.
jdaggett@8198 2248 However, this would cause a security leak since the contents of one page
jdaggett@8198 2249 would be able to affect other pages, something an attacker could use as an
jdaggett@8198 2250 attack vector. These restrictions do not affect caching behavior, fonts
jdaggett@8198 2251 are cached the same way other web resources are cached.
jdaggett@8198 2252
jdaggett@8198 2253 <p>This at-rule follows the forward-compatible parsing rules of CSS. Like
jdaggett@8198 2254 properties in a declaration block, declarations of any descriptors that
jdaggett@8311 2255 are not supported by the user agent must be ignored. <a
jdaggett@8311 2256 href="#at-font-face-rule"><code>@font-face</code></a> rules require a
jdaggett@8311 2257 font-family and src descriptor; if either of these are missing, the <a
jdaggett@8311 2258 href="#at-font-face-rule"><code>@font-face</code></a> rule is invalid and
jdaggett@8311 2259 must be ignored entirely.
jdaggett@1244 2260
jdaggett@1244 2261 <p>In cases where user agents have limited platform resources or implement
jdaggett@8311 2262 the ability to disable downloadable font resources, <a
jdaggett@8311 2263 href="#at-font-face-rule"><code>@font-face</code></a> rules must simply be
jdaggett@8311 2264 ignored; the behavior of individual descriptors as defined in this
jdaggett@8311 2265 specification should not be altered.
jdaggett@1662 2266
jdaggett@1662 2267 <h3 id=font-family-desc><span class=secno>4.2 </span>Font family: the <a
jdaggett@1662 2268 href="#descdef-font-family">font-family</a> descriptor</h3>
jdaggett@512 2269
jdaggett@512 2270 <table class=descdef>
jdaggett@512 2271 <tbody>
jdaggett@512 2272 <tr>
jdaggett@512 2273 <td>Name:
jdaggett@512 2274
jdaggett@8278 2275 <td><dfn id=descdef-font-family
jdaggett@8278 2276 title="font-family!!descriptor">font-family</dfn>
jdaggett@512 2277
jdaggett@512 2278 <tr>
jdaggett@512 2279 <td>Value:
jdaggett@512 2280
jdaggett@8225 2281 <td><a href="#family-name-value"><var>&lt;family-name&gt;</var></a>
jdaggett@890 2282
jdaggett@890 2283 <tr>
jdaggett@890 2284 <td><em>Initial:</em>
jdaggett@890 2285
jdaggett@890 2286 <td>N/A
jdaggett@512 2287 </table>
jdaggett@512 2288
jdaggett@525 2289 <p>This descriptor defines the font family name that will be used in all
jdaggett@8311 2290 CSS font family name matching. It is required for the <a
jdaggett@8311 2291 href="#at-font-face-rule"><code>@font-face</code></a> rule to be valid. It
jdaggett@8311 2292 overrides the font family names contained in the underlying font data. If
jdaggett@8311 2293 the font family name is the same as a font family available in a given
jdaggett@8311 2294 user's environment, it effectively hides the underlying font for documents
jdaggett@8311 2295 that use the stylesheet. This permits a web author to freely choose
jdaggett@8311 2296 font-family names without worrying about conflicts with font family names
jdaggett@8311 2297 present in a given user's environment. Likewise, platform substitutions
jdaggett@8311 2298 for a given font family name must not be used.
jdaggett@1244 2299
jdaggett@1662 2300 <h3 id=src-desc><span class=secno>4.3 </span>Font reference: the <a
jdaggett@1662 2301 href="#descdef-src">src</a> descriptor</h3>
jdaggett@512 2302
jdaggett@512 2303 <table class=descdef>
jdaggett@512 2304 <tbody>
jdaggett@512 2305 <tr>
jdaggett@512 2306 <td>Name:
jdaggett@512 2307
jdaggett@1662 2308 <td><dfn id=descdef-src>src</dfn>
jdaggett@512 2309
jdaggett@512 2310 <tr>
jdaggett@512 2311 <td>Value:
jdaggett@512 2312
jdaggett@8225 2313 <td>[ &lt;url> [format(&lt;string> #)]? | <a
jdaggett@8225 2314 href="#font-face-name-value"><var>&lt;font-face-name&gt;</var></a> ] #
jdaggett@890 2315
jdaggett@890 2316 <tr>
jdaggett@890 2317 <td><em>Initial:</em>
jdaggett@890 2318
jdaggett@890 2319 <td>N/A
jdaggett@512 2320 </table>
jdaggett@512 2321
jdaggett@899 2322 <p>This descriptor specifies the resource containing font data. It is
jdaggett@8311 2323 required for the <a href="#at-font-face-rule"><code>@font-face</code></a>
jdaggett@8311 2324 rule to be valid. Its value is a prioritized, comma-separated list of
jdaggett@8311 2325 external references or locally-installed font face names. When a font is
jdaggett@8311 2326 needed the user agent iterates over the set of references listed, using
jdaggett@8311 2327 the first one it can successfully activate. Fonts containing invalid data
jdaggett@8311 2328 or local font faces that are not found are ignored and the user agent
jdaggett@8311 2329 loads the next font in the list.
jdaggett@8272 2330
jdaggett@8272 2331 <p>As with other URLs in CSS, the URL may be relative, in which case it is
jdaggett@8311 2332 resolved relative to the location of the style sheet containing the <a
jdaggett@8311 2333 href="#at-font-face-rule"><code>@font-face</code></a> rule. In the case of
jdaggett@8311 2334 SVG fonts, the URL points to an element within a document containing SVG
jdaggett@8311 2335 font definitions. If the element reference is omitted, a reference to the
jdaggett@8311 2336 first defined font is implied. Similarly, font container formats that can
jdaggett@7096 2337 contain more than one font must load one and only one of the fonts for a
jdaggett@8311 2338 given <a href="#at-font-face-rule"><code>@font-face</code></a> rule.
jdaggett@8311 2339 Fragment identifiers are used to indicate which font to load. If a
jdaggett@8311 2340 container format lacks a defined fragment identifier scheme,
jdaggett@8311 2341 implementations should use a simple 1-based indexing scheme (e.g.
jdaggett@8311 2342 "font-collection#1" for the first font, "font-collection#2" for the second
jdaggett@8311 2343 font).
jdaggett@1244 2344
jdaggett@2527 2345 <pre>
jdaggett@8860 2346 src: url(fonts/simple.woff); /* load simple.woff relative to stylesheet location */
jdaggett@8860 2347 src: url(/fonts/simple.woff); /* load simple.woff from absolute location */
jdaggett@8860 2348 src: url(fonts.svg#simple); /* load SVG font with id 'simple' */
jdaggett@2527 2349 </pre>
jdaggett@2527 2350
jdaggett@8198 2351 <p>External references consist of a URL, followed by an optional hint
jdaggett@8198 2352 describing the format of the font resource referenced by that URL. The
jdaggett@2527 2353 format hint contains a comma-separated list of format strings that denote
jdaggett@2527 2354 well-known font formats. Conformant user agents must skip downloading a
jdaggett@2527 2355 font resource if the format hints indicate only unsupported or unknown
jdaggett@2527 2356 font formats. If no format hints are supplied, the user agent should
jdaggett@2527 2357 download the font resource.
jdaggett@2527 2358
jdaggett@2527 2359 <pre>
jdaggett@2527 2360 /* load WOFF font if possible, otherwise use OpenType font */
jdaggett@2527 2361 @font-face {
jdaggett@2527 2362 font-family: bodytext;
jdaggett@2527 2363 src: url(ideal-sans-serif.woff) format("woff"),
jdaggett@2527 2364 url(basic-sans-serif.ttf) format("opentype");
jdaggett@2527 2365 }
jdaggett@2527 2366 </pre>
jdaggett@2527 2367
jdaggett@2527 2368 <p>Format strings defined by this specification:
jdaggett@2527 2369
jdaggett@2527 2370 <table class=data id=fontformats>
jdaggett@2527 2371 <thead>
jdaggett@2527 2372 <tr>
jdaggett@2527 2373 <th>String
jdaggett@2527 2374
jdaggett@2527 2375 <th>Font Format
jdaggett@2527 2376
jdaggett@2527 2377 <th>Common extensions
jdaggett@2527 2378
jdaggett@2527 2379 <tbody>
jdaggett@2527 2380 <tr>
jdaggett@2527 2381 <th>"woff"
jdaggett@2527 2382
jdaggett@4624 2383 <td><a href="http://www.w3.org/TR/WOFF/">WOFF (Web Open Font Format)</a>
jdaggett@2527 2384
jdaggett@2527 2385 <td>.woff
jdaggett@2527 2386
jdaggett@2527 2387 <tr>
jdaggett@2527 2388 <th>"truetype"
jdaggett@2527 2389
jdaggett@4624 2390 <td><a
jdaggett@4624 2391 href="http://www.microsoft.com/typography/otspec/default.htm">TrueType</a>
jdaggett@2527 2392
jdaggett@2527 2393 <td>.ttf
jdaggett@2527 2394
jdaggett@2527 2395 <tr>
jdaggett@2527 2396 <th>"opentype"
jdaggett@2527 2397
jdaggett@4624 2398 <td><a
jdaggett@4624 2399 href="http://www.microsoft.com/typography/otspec/default.htm">OpenType</a>
jdaggett@2527 2400
jdaggett@2527 2401 <td>.ttf, .otf
jdaggett@2527 2402
jdaggett@2527 2403 <tr>
jdaggett@2527 2404 <th>"embedded-opentype"
jdaggett@2527 2405
jdaggett@4624 2406 <td><a
jdaggett@4624 2407 href="http://www.w3.org/Submission/2008/SUBM-EOT-20080305/">Embedded
jdaggett@4624 2408 OpenType</a>
jdaggett@2527 2409
jdaggett@2527 2410 <td>.eot
jdaggett@2527 2411
jdaggett@2527 2412 <tr>
jdaggett@2527 2413 <th>"svg"
jdaggett@2527 2414
jdaggett@4624 2415 <td><a href="http://www.w3.org/TR/SVG/fonts.html">SVG Font</a>
jdaggett@2527 2416
jdaggett@2527 2417 <td>.svg, .svgz
jdaggett@2527 2418 </table>
jdaggett@2527 2419
jdaggett@2527 2420 <p>Given the overlap in common usage between TrueType and OpenType, the
jdaggett@2527 2421 format hints "truetype" and "opentype" must be considered as synonymous; a
jdaggett@2527 2422 format hint of "opentype" does not imply that the font contains Postscript
jdaggett@2527 2423 CFF style glyph data or that it contains OpenType layout information (see
jdaggett@7377 2424 <a href="#platform-props-to-css">Appendix A</a> for more background on
jdaggett@7377 2425 this).
jdaggett@2527 2426
jdaggett@2527 2427 <p>When authors would prefer to use a locally available copy of a given
jdaggett@8198 2428 font and download it if it's not, <code>local()</code> can be used. The
jdaggett@8225 2429 locally-installed <dfn
jdaggett@8225 2430 id=font-face-name-value><var>&lt;font-face-name&gt;</var></dfn> argument
jdaggett@8272 2431 to <code>local()</code> is a format-specific string that uniquely
jdaggett@8272 2432 identifies a single font face within a larger family. The syntax for a <a
jdaggett@8225 2433 href="#font-face-name-value"><var>&lt;font-face-name&gt;</var></a> is a
jdaggett@8241 2434 unique font face name enclosed by "local(" and ")". The name can
jdaggett@8241 2435 optionally be enclosed in quotes. If unquoted, the unquoted font family
jdaggett@8241 2436 name processing conventions apply; the name must be a sequence of
jdaggett@8241 2437 identifiers separated by whitespace which is converted to a string by
jdaggett@8241 2438 joining the identifiers together separated by a single space.
jdaggett@2527 2439
jdaggett@2527 2440 <pre>
jdaggett@2527 2441 /* regular face of Gentium */
jdaggett@573 2442 @font-face {
jdaggett@2527 2443 font-family: MyGentium;
jdaggett@8860 2444 src: local(Gentium), /* use locally available Gentium */
jdaggett@8860 2445 url(Gentium.woff); /* otherwise, download it */
jdaggett@573 2446 }
jdaggett@573 2447 </pre>
jdaggett@573 2448
jdaggett@8241 2449 <p>For OpenType and TrueType fonts, this string is used to match only the
jdaggett@8241 2450 Postscript name or the full font name in the name table of locally
jdaggett@8241 2451 available fonts. Which type of name is used varies by platform and font,
jdaggett@8241 2452 so authors should include both of these names to assure proper matching
jdaggett@8241 2453 across platforms. Platform substitutions for a given font name must not be
jdaggett@8241 2454 used.
jdaggett@2527 2455
jdaggett@2527 2456 <pre>
jdaggett@2527 2457 /* bold face of Gentium */
jdaggett@2527 2458 @font-face {
jdaggett@2527 2459 font-family: MyGentium;
jdaggett@8860 2460 src: local(Gentium Bold), /* full font name */
jdaggett@8860 2461 local(Gentium-Bold), /* Postscript name */
jdaggett@8860 2462 url(GentiumBold.woff); /* otherwise, download it */
jdaggett@2527 2463 font-weight: bold;
jdaggett@2527 2464 }
jdaggett@2527 2465 </pre>
jdaggett@2527 2466
jdaggett@8311 2467 <p>Just as a <a href="#at-font-face-rule"><code>@font-face</code></a> rule
jdaggett@8311 2468 specifies the characteristics of a single font within a family, the unique
jdaggett@8311 2469 name used with <code>local()</code> specifies a single font, not an entire
jdaggett@8311 2470 font family. Defined in terms of OpenType font data, the Postscript name
jdaggett@8311 2471 is found in the font's <a
jdaggett@2527 2472 href="http://www.microsoft.com/typography/otspec/name.htm">name table</a>,
jdaggett@2527 2473 in the name record with nameID = 6 (see <a href="#OPENTYPE"
jdaggett@2556 2474 rel=biblioentry>[OPENTYPE]<!--{{!OPENTYPE}}--></a> for more details). The
jdaggett@2527 2475 Postscript name is the commonly used key for all fonts on OSX and for
jdaggett@2527 2476 Postscript CFF fonts under Windows. The full font name (nameID = 4) is
jdaggett@2527 2477 used as a unique key for fonts with TrueType glyphs on Windows.
jdaggett@2527 2478
jdaggett@2527 2479 <p>For OpenType fonts with multiple localizations of the full font name,
jdaggett@2527 2480 the US English version is used (language ID = 0x409 for Windows and
jdaggett@2527 2481 language ID = 0 for Macintosh) or the first localization when a US English
jdaggett@2527 2482 full font name is not available (the OpenType specification recommends
jdaggett@2527 2483 that <a href="http://www.microsoft.com/typography/otspec/recom.htm">all
jdaggett@2527 2484 fonts minimally include US English names</a>). User agents that also match
jdaggett@2527 2485 other full font names, e.g. matching the Dutch name when the current
jdaggett@2527 2486 system locale is set to Dutch, are considered non-conformant. This is done
jdaggett@2527 2487 not to prefer English but to avoid matching inconsistencies across font
jdaggett@2527 2488 versions and OS localizations, since font style names (e.g. "Bold") are
jdaggett@2527 2489 frequently localized into many languages and the set of localizations
jdaggett@2527 2490 available varies widely across platform and font version. User agents that
jdaggett@2527 2491 match a concatenation of family name (nameID = 1) with style name (nameID
jdaggett@2527 2492 = 2) are considered non-conformant.
jdaggett@2527 2493
jdaggett@2527 2494 <p>This also allows for referencing faces that belong to larger families
jdaggett@2527 2495 that cannot otherwise be referenced.
jdaggett@2527 2496
jdaggett@2527 2497 <div class=example>
jdaggett@525 2498 <p>Use a local font or reference an SVG font in another document:</p>
jdaggett@525 2499
jdaggett@525 2500 <pre>
jdaggett@525 2501 @font-face {
jdaggett@525 2502 font-family: Headline;
jdaggett@8277 2503 src: local(Futura-Medium),
jdaggett@1148 2504 url(fonts.svg#MyGeometricModern) format("svg");
jdaggett@525 2505 }
jdaggett@525 2506 </pre>
jdaggett@525 2507
jdaggett@525 2508 <p>Create an alias for local Japanese fonts on different platforms:</p>
jdaggett@525 2509
jdaggett@525 2510 <pre>
jdaggett@525 2511 @font-face {
jdaggett@2527 2512 font-family: jpgothic;
jdaggett@525 2513 src: local(HiraKakuPro-W3), local(Meiryo), local(IPAPGothic);
jdaggett@525 2514 }
jdaggett@525 2515 </pre>
jdaggett@525 2516
jdaggett@525 2517 <p>Reference a font face that cannot be matched within a larger family:</p>
jdaggett@525 2518
jdaggett@525 2519 <pre>
jdaggett@525 2520 @font-face {
jdaggett@525 2521 font-family: Hoefler Text Ornaments;
jdaggett@525 2522 /* has the same font properties as Hoefler Text Regular */
jdaggett@8277 2523 src: local(HoeflerText-Ornaments);
jdaggett@525 2524 }
jdaggett@525 2525 </pre>
jdaggett@2527 2526
jdaggett@8198 2527 <p>Since localized fullnames never match, a document with the header style
jdaggett@8198 2528 rules below would always render using the default serif font, regardless
jdaggett@8198 2529 whether a particular system locale parameter is set to Finnish or not:</p>
jdaggett@1662 2530
jdaggett@1662 2531 <pre>
jdaggett@1662 2532 @font-face {
jdaggett@1662 2533 font-family: SectionHeader;
jdaggett@6653 2534 src: local("Arial Lihavoitu"); /* Finnish fullname for Arial Bold, should fail */
jdaggett@1662 2535 font-weight: bold;
jdaggett@1662 2536 }
jdaggett@1662 2537
jdaggett@1662 2538 h2 { font-family: SectionHeader, serif; }
jdaggett@1662 2539 </pre>
jdaggett@1662 2540
jdaggett@8198 2541 <p>A conformant user agent would never load the font ‘<code
jdaggett@1662 2542 class=css>gentium.eot</code>’ in the example below, since it is
jdaggett@4624 2543 included in the first definition of the ‘<a href="#descdef-src"><code
jdaggett@4624 2544 class=property>src</code></a>’ descriptor which is overridden by the
jdaggett@8311 2545 second definition in the same <a
jdaggett@8311 2546 href="#at-font-face-rule"><code>@font-face</code></a> rule:</p>
jdaggett@1662 2547
jdaggett@1662 2548 <pre>
jdaggett@1662 2549 @font-face {
jdaggett@1662 2550 font-family: MainText;
jdaggett@8860 2551 src: url(gentium.eot); /* for use with older user agents */
jdaggett@8860 2552 src: local("Gentium"), url(gentium.woff); /* Overrides src definition */
jdaggett@1662 2553 }
jdaggett@1662 2554 </pre>
jdaggett@1662 2555 </div>
jdaggett@1662 2556
jdaggett@1662 2557 <h3 id=font-prop-desc><span class=secno>4.4 </span>Font property
jdaggett@1662 2558 descriptors: the <a href="#descdef-font-style">font-style</a>, <a
jdaggett@1662 2559 href="#descdef-font-weight">font-weight</a>, <a
jdaggett@1662 2560 href="#descdef-font-stretch">font-stretch</a> descriptors</h3>
jdaggett@518 2561
jdaggett@518 2562 <table class=descdef>
jdaggett@518 2563 <tbody>
jdaggett@518 2564 <tr>
jdaggett@518 2565 <td>Name:
jdaggett@518 2566
jdaggett@8278 2567 <td><dfn id=descdef-font-style
jdaggett@8278 2568 title="font-style!!descriptor">font-style</dfn>
jdaggett@518 2569
jdaggett@518 2570 <tr>
jdaggett@518 2571 <td>Value:
jdaggett@518 2572
jdaggett@545 2573 <td>normal | italic | oblique
jdaggett@890 2574
jdaggett@890 2575 <tr>
jdaggett@890 2576 <td><em>Initial:</em>
jdaggett@890 2577
jdaggett@890 2578 <td>normal
jdaggett@518 2579 </table>
jdaggett@518 2580
jdaggett@518 2581 <table class=descdef>
jdaggett@518 2582 <tbody>
jdaggett@518 2583 <tr>
jdaggett@518 2584 <td>Name:
jdaggett@518 2585
jdaggett@8278 2586 <td><dfn id=descdef-font-weight
jdaggett@8278 2587 title="font-weight!!descriptor">font-weight</dfn>
jdaggett@518 2588
jdaggett@518 2589 <tr>
jdaggett@518 2590 <td>Value:
jdaggett@518 2591
jdaggett@545 2592 <td>normal | bold | 100 | 200 | 300 | 400 | 500 | 600 | 700 | 800 | 900
jdaggett@890 2593
jdaggett@890 2594 <tr>
jdaggett@890 2595 <td><em>Initial:</em>
jdaggett@890 2596
jdaggett@890 2597 <td>normal
jdaggett@518 2598 </table>
jdaggett@518 2599
jdaggett@518 2600 <table class=descdef>
jdaggett@518 2601 <tbody>
jdaggett@518 2602 <tr>
jdaggett@518 2603 <td>Name:
jdaggett@518 2604
jdaggett@8278 2605 <td><dfn id=descdef-font-stretch
jdaggett@8278 2606 title="font-stretch!!descriptor">font-stretch</dfn>
jdaggett@518 2607
jdaggett@518 2608 <tr>
jdaggett@518 2609 <td>Value:
jdaggett@518 2610
jdaggett@545 2611 <td>normal | ultra-condensed | extra-condensed | condensed |
jdaggett@518 2612 semi-condensed | semi-expanded | expanded | extra-expanded |
jdaggett@525 2613 ultra-expanded
jdaggett@890 2614
jdaggett@890 2615 <tr>
jdaggett@890 2616 <td><em>Initial:</em>
jdaggett@890 2617
jdaggett@890 2618 <td>normal
jdaggett@518 2619 </table>
jdaggett@518 2620
jdaggett@573 2621 <p>These descriptors define the characteristics of a font face and are used
jdaggett@573 2622 in the process of matching styles to specific faces. For a font family
jdaggett@8311 2623 defined with several <a
jdaggett@8311 2624 href="#at-font-face-rule"><code>@font-face</code></a> rules, user agents
jdaggett@8311 2625 can either download all faces in the family or use these descriptors to
jdaggett@8311 2626 selectively download font faces that match actual styles used in document.
jdaggett@8311 2627 The values for these descriptors are the same as those for the
jdaggett@8311 2628 corresponding font properties except that relative keywords are not
jdaggett@8311 2629 allowed, ‘<a href="#bolder"><code class=property>bolder</code></a>’
jdaggett@8311 2630 and ‘<a href="#lighter"><code class=property>lighter</code></a>’. If
jdaggett@8311 2631 these descriptors are omitted, initial values are assumed.
jdaggett@890 2632
jdaggett@890 2633 <p>The value for these font face style attributes is used in place of the
jdaggett@890 2634 style implied by the underlying font data. This allows authors to combine
jdaggett@890 2635 faces in flexible combinations, even in situations where the original font
jdaggett@890 2636 data was arranged differently. User agents that implement synthetic
jdaggett@8272 2637 bolding and obliquing must only apply synthetic styling in cases where the
jdaggett@8272 2638 font descriptors imply this is needed, rather than based on the style
jdaggett@890 2639 attributes implied by the font data.
jdaggett@573 2640
jdaggett@1662 2641 <h3 id=unicode-range-desc><span class=secno>4.5 </span>Character range: the
jdaggett@1662 2642 <a href="#descdef-unicode-range">unicode-range</a> descriptor</h3>
jdaggett@518 2643
jdaggett@518 2644 <table class=descdef>
jdaggett@518 2645 <tbody>
jdaggett@518 2646 <tr>
jdaggett@518 2647 <td>Name:
jdaggett@518 2648
jdaggett@1662 2649 <td><dfn id=descdef-unicode-range>unicode-range</dfn>
jdaggett@518 2650
jdaggett@518 2651 <tr>
jdaggett@518 2652 <td>Value:
jdaggett@518 2653
jdaggett@8225 2654 <td><a href="#urange-value"><var>&lt;urange&gt;</var></a> #
jdaggett@890 2655
jdaggett@890 2656 <tr>
jdaggett@890 2657 <td><em>Initial:</em>
jdaggett@890 2658
jdaggett@1148 2659 <td>U+0-10FFFF
jdaggett@518 2660 </table>
jdaggett@518 2661
jdaggett@8213 2662 <p>This descriptor defines the set of Unicode codepoints that may be
jdaggett@8213 2663 supported by the font face for which it is declared. The descriptor value
jdaggett@8225 2664 is a comma-delimited list of Unicode range (<a
jdaggett@8225 2665 href="#urange-value"><var>&lt;urange&gt;</var></a>) values. The union of
jdaggett@8225 2666 these ranges defines the set of codepoints that serves as a hint for user
jdaggett@8225 2667 agents when deciding whether or not to download a font resource for a
jdaggett@8225 2668 given text run.
jdaggett@8225 2669
jdaggett@8225 2670 <p>Each <dfn id=urange-value><var>&lt;urange&gt;</var></dfn> value is a <a
jdaggett@8225 2671 href="http://www.w3.org/TR/CSS21/syndata.html#tokenization"><code
jdaggett@8225 2672 title="UNICODE-RANGE token">UNICODE-RANGE</code></a> token made up of a
jdaggett@8225 2673 "U+" or "u+" prefix followed by a codepoint range in one of the three
jdaggett@8241 2674 forms listed below. Ranges that do not fit one of the these forms are
jdaggett@8241 2675 invalid and cause the declaration to be ignored.
jdaggett@8241 2676
jdaggett@8241 2677 <dl>
jdaggett@8241 2678 <dt>single codepoint (e.g. U+416)
jdaggett@8241 2679
jdaggett@8241 2680 <dd>a valid Unicode codepoint, represented as one to six hexadecimal
jdaggett@8241 2681 digits
jdaggett@8241 2682
jdaggett@8246 2683 <dt>interval range (e.g. U+400-4ff)
jdaggett@8241 2684
jdaggett@8241 2685 <dd>represented as two hyphen-separated valid Unicode codepoints
jdaggett@8241 2686 indicating the inclusive start and end codepoints of a range
jdaggett@8241 2687
jdaggett@8246 2688 <dt>wildcard range (e.g. U+4??)
jdaggett@8241 2689
jdaggett@8241 2690 <dd>defined by the set of codepoints implied when trailing ‘<code
jdaggett@8246 2691 class=css>?</code>’ characters signify any hexadeximal digit
jdaggett@8241 2692 </dl>
jdaggett@573 2693
jdaggett@8213 2694 <p>Individual codepoints are written using hexadecimal values that
jdaggett@8213 2695 correspond to <a href="http://www.unicode.org/charts/">Unicode character
jdaggett@8225 2696 codepoints</a>. Valid Unicode codepoint values vary between 0 and 10FFFF
jdaggett@8225 2697 inclusive. Digit values of codepoints are ASCII case-insensitive. For
jdaggett@8360 2698 interval ranges, the start and end codepoints are valid Unicode values and
jdaggett@8360 2699 the end codepoint is greater than or equal to the start codepoint.
jdaggett@8225 2700
jdaggett@8225 2701 <p>Wildcard ranges specified with ‘?’ that lack an initial digit (e.g.
jdaggett@8225 2702 "U+???") are valid and equivalent to a wildcard range with an initial zero
jdaggett@8225 2703 digit (e.g. "U+0???" = "U+0000-0FFF"). Wildcard ranges that extend beyond
jdaggett@8225 2704 the range of valid Unicode codepoints are invalid. Because of this, the
jdaggett@8225 2705 maximum number of trailing ‘<code class=css>?</code>’ wildcard
jdaggett@8272 2706 characters is five, even though the <a
jdaggett@8225 2707 href="http://www.w3.org/TR/CSS21/syndata.html#tokenization"><code
jdaggett@8225 2708 title="UNICODE-RANGE token">UNICODE-RANGE</code></a> token accepts six.
jdaggett@8213 2709
jdaggett@8213 2710 <p>Within the comma-delimited list of Unicode ranges in a ‘<a
jdaggett@8213 2711 href="#descdef-unicode-range"><code
jdaggett@8213 2712 class=property>unicode-range</code></a>’ descriptor declaration, ranges
jdaggett@8241 2713 may overlap. The union of these ranges defines the set of codepoints for
jdaggett@8241 2714 which the corresponding font may be used. User agents must not download or
jdaggett@8241 2715 use the font for codepoints outside this set. User agents may normalize
jdaggett@8241 2716 the list of ranges into a list that is different but represents the same
jdaggett@8241 2717 set of codepoints.
jdaggett@8213 2718
jdaggett@8272 2719 <p>The associated font might not contain glyphs for the entire set of
jdaggett@8213 2720 codepoints defined by the ‘<a href="#descdef-unicode-range"><code
jdaggett@8213 2721 class=property>unicode-range</code></a>’ descriptor. When the font is
jdaggett@8391 2722 used, the <dfn id=effective-character-map>effective character map</dfn> is
jdaggett@8225 2723 the intersection of the codepoints defined by ‘<a
jdaggett@8225 2724 href="#descdef-unicode-range"><code
jdaggett@8225 2725 class=property>unicode-range</code></a>’ with the font's <a
jdaggett@8225 2726 href="#character-map"><em>character map</em></a>. This allows authors to
jdaggett@8225 2727 define supported ranges in terms of broad ranges without worrying about
jdaggett@8225 2728 the precise codepoint ranges supported by the underlying font.
jdaggett@8225 2729
jdaggett@8225 2730 <h3 id=composite-fonts><span class=secno>4.6 </span>Using character ranges
jdaggett@8225 2731 to define composite fonts</h3>
jdaggett@8225 2732
jdaggett@8311 2733 <p>Multiple <a href="#at-font-face-rule"><code>@font-face</code></a> rules
jdaggett@8311 2734 with different unicode ranges for the same family and style descriptor
jdaggett@8311 2735 values can be used to create composite fonts that mix the glyphs from
jdaggett@8311 2736 different fonts for different scripts. This can be used to combine fonts
jdaggett@8311 2737 that only contain glyphs for a single script (e.g. Latin, Greek, Cyrillic)
jdaggett@8311 2738 or it can be used by authors as a way of segmenting a font into fonts for
jdaggett@8311 2739 commonly used characters and less frequently used characters. Since the
jdaggett@8311 2740 user agent will only pull down the fonts it needs this helps reduce page
jdaggett@8311 2741 bandwidth.
jdaggett@8311 2742
jdaggett@8311 2743 <p>If the unicode ranges overlap for a set of <a
jdaggett@8311 2744 href="#at-font-face-rule"><code>@font-face</code></a> rules with the same
jdaggett@8311 2745 family and style descriptor values, the rules are ordered in the reverse
jdaggett@8311 2746 order they were defined; the last rule defined is the first to be checked
jdaggett@8311 2747 for a given character.
jdaggett@890 2748
jdaggett@890 2749 <p>Example ranges for specific languages or characters:
jdaggett@518 2750
jdaggett@518 2751 <dl>
jdaggett@529 2752 <dt>unicode-range: U+A5;
jdaggett@529 2753
jdaggett@1149 2754 <dd>a single code point, the yen/yuan symbol
jdaggett@529 2755
jdaggett@1148 2756 <dt>unicode-range: U+0-7F;
jdaggett@1148 2757
jdaggett@1148 2758 <dd>code range for basic ASCII characters
jdaggett@1148 2759
jdaggett@529 2760 <dt>unicode-range: U+590-5ff;
jdaggett@529 2761
jdaggett@529 2762 <dd>code range for Hebrew characters
jdaggett@529 2763
jdaggett@529 2764 <dt>unicode-range: U+A5, U+4E00-9FFF, U+30??, U+FF00-FF9F;
jdaggett@529 2765
jdaggett@529 2766 <dd>code range for Japanese kanji, hiragana and katakana characters plus
jdaggett@529 2767 yen/yuan symbol
jdaggett@518 2768 </dl>
jdaggett@518 2769
jdaggett@529 2770 <div class=example>
jdaggett@531 2771 <p>The BBC provides news services in a wide variety of languages, many
jdaggett@8311 2772 that are not well supported across all platforms. Using an <a
jdaggett@8311 2773 href="#at-font-face-rule"><code>@font-face</code></a> rule, the BBC could
jdaggett@8311 2774 provide a font for any of these languages, as it already does via a
jdaggett@8311 2775 manual font download.</p>
jdaggett@531 2776
jdaggett@531 2777 <pre>
jdaggett@531 2778 @font-face {
jdaggett@531 2779 font-family: BBCBengali;
jdaggett@8860 2780 src: url(fonts/BBCBengali.woff) format("woff");
jdaggett@531 2781 unicode-range: U+00-FF, U+980-9FF;
jdaggett@531 2782 }
jdaggett@531 2783 </pre>
jdaggett@529 2784 </div>
jdaggett@529 2785
jdaggett@529 2786 <div class=example>
jdaggett@531 2787 <p>Technical documents often require a wide range of symbols. The STIX
jdaggett@531 2788 Fonts project is one project aimed at providing fonts to support a wide
jdaggett@531 2789 range of technical typesetting in a standardized way. The example below
jdaggett@531 2790 shows the use of a font that provides glyphs for many of the mathematical
jdaggett@531 2791 and technical symbol ranges within Unicode:</p>
jdaggett@531 2792
jdaggett@531 2793 <pre>
jdaggett@531 2794 @font-face {
jdaggett@531 2795 font-family: STIXGeneral;
jdaggett@531 2796 src: local(STIXGeneral), url(/stixfonts/STIXGeneral.otf);
jdaggett@531 2797 unicode-range: U+000-49F, U+2000-27FF, U+2900-2BFF, U+1D400-1D7FF;
jdaggett@531 2798 }
jdaggett@531 2799 </pre>
jdaggett@529 2800 </div>
jdaggett@529 2801
jdaggett@529 2802 <div class=example>
jdaggett@529 2803 <p>This example shows how an author can override the glyphs used for Latin
jdaggett@529 2804 characters in a Japanese font with glyphs from a different font. The
jdaggett@529 2805 first rule specifies no range so it defaults to the entire range. The
jdaggett@529 2806 range specified in the second rule overlaps but takes precedence because
jdaggett@529 2807 it is defined later.</p>
jdaggett@529 2808
jdaggett@529 2809 <pre>
jdaggett@529 2810 @font-face {
jdaggett@529 2811 font-family: JapaneseWithGentium;
jdaggett@529 2812 src: local(MSMincho);
jdaggett@529 2813 /* no range specified, defaults to entire range */
jdaggett@529 2814 }
jdaggett@529 2815
jdaggett@529 2816 @font-face {
jdaggett@529 2817 font-family: JapaneseWithGentium;
jdaggett@8860 2818 src: url(../fonts/Gentium.woff);
jdaggett@529 2819 unicode-range: U+0-2FF;
jdaggett@529 2820 }
jdaggett@529 2821 </pre>
jdaggett@529 2822 </div>
jdaggett@1148 2823
jdaggett@1148 2824 <div class=example>
jdaggett@1148 2825 <p>Consider a family constructed to optimize bandwidth by separating out
jdaggett@1148 2826 Latin, Japanese and other characters into different font files:</p>
jdaggett@1148 2827
jdaggett@1148 2828 <pre>
jdaggett@1148 2829 /* fallback font - size: 4.5MB */
jdaggett@1148 2830 @font-face {
jdaggett@1148 2831 font-family: DroidSans;
jdaggett@8860 2832 src: url(DroidSansFallback.woff);
jdaggett@1148 2833 /* no range specified, defaults to entire range */
jdaggett@1148 2834 }
jdaggett@1148 2835
jdaggett@1148 2836 /* Japanese glyphs - size: 1.2MB */
jdaggett@1148 2837 @font-face {
jdaggett@1148 2838 font-family: DroidSans;
jdaggett@8860 2839 src: url(DroidSansJapanese.woff);
jdaggett@1148 2840 unicode-range: U+3000-9FFF, U+ff??;
jdaggett@1148 2841 }
jdaggett@1148 2842
jdaggett@8277 2843 /* Latin, Greek, Cyrillic along with some
jdaggett@1148 2844 punctuation and symbols - size: 190KB */
jdaggett@1148 2845 @font-face {
jdaggett@1148 2846 font-family: DroidSans;
jdaggett@8860 2847 src: url(DroidSans.woff);
jdaggett@1148 2848 unicode-range: U+000-5FF, U+1e00-1fff, U+2000-2300;
jdaggett@1148 2849 }
jdaggett@1148 2850 </pre>
jdaggett@1148 2851
jdaggett@1148 2852 <p>For simple Latin text, only the font for Latin characters is
jdaggett@1148 2853 downloaded:</p>
jdaggett@1148 2854
jdaggett@1148 2855 <pre>
jdaggett@1148 2856 body { font-family: DroidSans; }
jdaggett@1148 2857
jdaggett@1148 2858 &lt;p>This is that&lt;/p>
jdaggett@1148 2859 </pre>
jdaggett@1148 2860
jdaggett@1148 2861 <p>In this case the user agent first checks the unicode-range for the font
jdaggett@8860 2862 containing Latin characters (DroidSans.woff). Since all the characters
jdaggett@1148 2863 above are in the range U+0-5FF, the user agent downloads the font and
jdaggett@1148 2864 renders the text with that font.</p>
jdaggett@1148 2865
jdaggett@1148 2866 <p>Next, consider text that makes use of an arrow character (⇨):</p>
jdaggett@1148 2867
jdaggett@1148 2868 <pre>
jdaggett@1148 2869 &lt;p>This &amp;#x21e8; that&lt;p>
jdaggett@1148 2870 </pre>
jdaggett@1148 2871
jdaggett@1148 2872 <p>The user agent again first checks the unicode-range of the font
jdaggett@1149 2873 containing Latin characters. Since U+2000-2300 includes the arrow code
jdaggett@1149 2874 point (U+21E8), the user agent downloads the font. For this character
jdaggett@1148 2875 however the Latin font does not have a matching glyph, so the effective
jdaggett@1149 2876 unicode-range used for font matching excludes this code point. Next, the
jdaggett@1148 2877 user agent evaluates the Japanese font. The unicode-range for the
jdaggett@1148 2878 Japanese font, U+3000-9FFF and U+ff??, does not include U+21E8, so the
jdaggett@1662 2879 user agent does not download the Japanese font. Next the fallback font is
jdaggett@8311 2880 considered. The <a href="#at-font-face-rule"><code>@font-face</code></a>
jdaggett@8311 2881 rule for the fallback font does not define unicode-range so its value
jdaggett@8311 2882 defaults to the range of all Unicode code points. The fallback font is
jdaggett@8311 2883 downloaded and used to render the arrow character.</p>
jdaggett@1148 2884 </div>
jdaggett@890 2885
jdaggett@8225 2886 <h3 id=font-rend-desc><span class=secno>4.7 </span>Font features: the <a
jdaggett@1662 2887 href="#descdef-font-variant">font-variant</a> and <a
jdaggett@1662 2888 href="#descdef-font-feature-settings">font-feature-settings</a>
jdaggett@1662 2889 descriptors</h3>
jdaggett@1662 2890
jdaggett@1662 2891 <table class=descdef>
jdaggett@1662 2892 <tbody>
jdaggett@1662 2893 <tr>
jdaggett@1662 2894 <td>Name:
jdaggett@1662 2895
jdaggett@8278 2896 <td><dfn id=descdef-font-variant
jdaggett@8278 2897 title="font-variant!!descriptor">font-variant</dfn>
jdaggett@1662 2898
jdaggett@1662 2899 <tr>
jdaggett@1662 2900 <td>Value:
jdaggett@1662 2901
jdaggett@8278 2902 <td><a href="#font-variant-normal-value"
jdaggett@8278 2903 title="normal!!font-variant">normal</a> | <a
jdaggett@8278 2904 href="#font-variant-none-value" title="none!!font-variant">none</a> | [
jdaggett@8278 2905 <a href="#common-lig-values"><var>&lt;common-lig-values&gt;</var></a>
jdaggett@8278 2906 || <a
jdaggett@8225 2907 href="#discretionary-lig-values"><var>&lt;discretionary-lig-values&gt;</var></a>
jdaggett@8225 2908 || <a
jdaggett@8225 2909 href="#historical-lig-values"><var>&lt;historical-lig-values&gt;</var></a>
jdaggett@8225 2910 || <a
jdaggett@8225 2911 href="#contextual-alt-values"><var>&lt;contextual-alt-values&gt;</var></a>
jdaggett@8225 2912 || <a href="#stylistic"><var
jdaggett@8225 2913 title=stylistic>stylistic(&lt;feature-value-name&gt;)</var></a> || <a
jdaggett@8225 2914 href="#historical-forms"><var>historical-forms</var></a> || <a
jdaggett@8225 2915 href="#styleset"><var
jdaggett@8225 2916 title=styleset>styleset(&lt;feature-value-name&gt; #)</var></a> || <a
jdaggett@8225 2917 href="#character-variant"><var
jdaggett@8225 2918 title=character-variant>character-variant(&lt;feature-value-name&gt;
jdaggett@8225 2919 #)</var></a> || <a href="#swash"><var
jdaggett@8225 2920 title=swash>swash(&lt;feature-value-name&gt;)</var></a> || <a
jdaggett@8225 2921 href="#ornaments"><var
jdaggett@8225 2922 title=ornaments>ornaments(&lt;feature-value-name&gt;)</var></a> || <a
jdaggett@8225 2923 href="#annotation"><var
jdaggett@8225 2924 title=annotation>annotation(&lt;feature-value-name&gt;)</var></a> || [
jdaggett@8225 2925 <a href="#small-caps"><i>small-caps</i></a> | <a
jdaggett@8225 2926 href="#all-small-caps"><i>all-small-caps</i></a> | <a
jdaggett@8225 2927 href="#petite-caps"><i>petite-caps</i></a> | <a
jdaggett@8225 2928 href="#all-petite-caps"><i>all-petite-caps</i></a> | <a
jdaggett@8225 2929 href="#unicase"><i>unicase</i></a> | <a
jdaggett@8225 2930 href="#titling-caps"><i>titling-caps</i></a> ] || <a
jdaggett@8225 2931 href="#numeric-figure-values"><var>&lt;numeric-figure-values&gt;</var></a>
jdaggett@8225 2932 || <a
jdaggett@8225 2933 href="#numeric-spacing-values"><var>&lt;numeric-spacing-values&gt;</var></a>
jdaggett@8225 2934 || <a
jdaggett@8225 2935 href="#numeric-fraction-values"><var>&lt;numeric-fraction-values&gt;</var></a>
jdaggett@8225 2936 || <a href="#ordinal"><i>ordinal</i></a> || <a
jdaggett@8225 2937 href="#slashed-zero"><i>slashed-zero</i></a> || <a
jdaggett@8225 2938 href="#east-asian-variant-values"><var>&lt;east-asian-variant-values&gt;</var></a>
jdaggett@8225 2939 || <a
jdaggett@8225 2940 href="#east-asian-width-values"><var>&lt;east-asian-width-values&gt;</var></a>
jdaggett@8225 2941 || <a href="#ruby"><i>ruby</i></a> ]
jdaggett@1662 2942
jdaggett@1662 2943 <tr>
jdaggett@1662 2944 <td><em>Initial:</em>
jdaggett@1662 2945
jdaggett@1662 2946 <td>normal
jdaggett@1662 2947 </table>
jdaggett@1662 2948
jdaggett@1662 2949 <table class=descdef>
jdaggett@1662 2950 <tbody>
jdaggett@1662 2951 <tr>
jdaggett@1662 2952 <td>Name:
jdaggett@1662 2953
jdaggett@8278 2954 <td><dfn id=descdef-font-feature-settings
jdaggett@8278 2955 title="font-feature-settings!!descriptor">font-feature-settings</dfn>
jdaggett@1662 2956
jdaggett@1662 2957 <tr>
jdaggett@1662 2958 <td>Value:
jdaggett@1662 2959
jdaggett@8278 2960 <td><a href="#font-feature-settings-normal-value"
jdaggett@8278 2961 title="normal!!font-feature-settings">normal</a> | <a
jdaggett@8225 2962 href="#feature-tag-value"><var>&lt;feature-tag-value&gt;</var></a> #
jdaggett@1662 2963
jdaggett@1662 2964 <tr>
jdaggett@1662 2965 <td><em>Initial:</em>
jdaggett@1662 2966
jdaggett@1662 2967 <td>normal
jdaggett@1662 2968 </table>
jdaggett@1662 2969
jdaggett@8213 2970 <p>These descriptors define initial settings that apply when the font
jdaggett@8311 2971 defined by an <a href="#at-font-face-rule"><code>@font-face</code></a>
jdaggett@8311 2972 rule is rendered. They do not affect font selection. Values are identical
jdaggett@8311 2973 to those defined for the corresponding <a href="#propdef-font-variant"
jdaggett@8278 2974 title="font-variant!!property">‘<code
jdaggett@8279 2975 class=property>font-variant</code>’</a> and <a
jdaggett@8279 2976 href="#propdef-font-feature-settings"
jdaggett@8279 2977 title="font-feature-settings!!property">‘<code
jdaggett@8279 2978 class=property>font-feature-settings</code>’</a> properties defined
jdaggett@8279 2979 below except that the value ‘<code class=property>inherit</code>’ is
jdaggett@8279 2980 omitted. When multiple font feature descriptors or properties are used,
jdaggett@8279 2981 the cumulative effect on text rendering is detailed in the section <a
jdaggett@8031 2982 href="#font-feature-resolution">Font Feature Resolution</a> below. In
jdaggett@8278 2983 cases where specific values define synthesized fallback for certain <a
jdaggett@8278 2984 href="#propdef-font-variant" title="font-variant!!property">‘<code
jdaggett@8278 2985 class=property>font-variant</code>’</a> subproperties, the same
jdaggett@8031 2986 synthesized fallback applies when used within those values are used with
jdaggett@8278 2987 the <a href="#descdef-font-style" title="font-style!!descriptor">‘<code
jdaggett@8031 2988 class=property>font-variant</code>’</a> descriptor.
jdaggett@1662 2989
jdaggett@8225 2990 <h3 id=font-face-loading><span class=secno>4.8 </span>Font loading
jdaggett@2563 2991 guidelines</h3>
jdaggett@2563 2992
jdaggett@8311 2993 <p>The <a href="#at-font-face-rule"><code>@font-face</code></a> rule is
jdaggett@8311 2994 designed to allow lazy loading of font resources that are only downloaded
jdaggett@8311 2995 when used within a document. A stylesheet can include <a
jdaggett@8311 2996 href="#at-font-face-rule"><code>@font-face</code></a> rules for a library
jdaggett@8311 2997 of fonts of which only a select set are used; user agents must only
jdaggett@8311 2998 download those fonts that are referred to within the style rules
jdaggett@8311 2999 applicable to a given page. User agents that download all fonts defined in
jdaggett@8311 3000 <a href="#at-font-face-rule"><code>@font-face</code></a> rules without
jdaggett@8311 3001 considering whether those fonts are in fact used within a page are
jdaggett@8311 3002 considered non-conformant. In cases where a font might be downloaded in
jdaggett@8360 3003 character fallback cases, user agents may download a font if it's
jdaggett@8360 3004 contained within the computed value of <a href="#propdef-font-family"
jdaggett@8360 3005 title="font-family!!property">‘<code
jdaggett@8360 3006 class=property>font-family</code>’</a> for a given text run.
jdaggett@2563 3007
jdaggett@2563 3008 <pre>
jdaggett@2563 3009 @font-face {
jdaggett@2563 3010 font-family: GeometricModern;
jdaggett@8860 3011 src: url(font.woff);
jdaggett@2563 3012 }
jdaggett@2563 3013
jdaggett@2563 3014 p {
jdaggett@2563 3015 /* font will be downloaded for pages with p elements */
jdaggett@2563 3016 font-family: GeometricModern, sans-serif;
jdaggett@2563 3017 }
jdaggett@2563 3018
jdaggett@2563 3019 h2 {
jdaggett@2563 3020 /* font may be downloaded for pages with h2 elements, even if Futura is available locally */
jdaggett@2563 3021 font-family: Futura, GeometricModern, sans-serif;
jdaggett@2563 3022 }
jdaggett@2563 3023 </pre>
jdaggett@2563 3024
jdaggett@2563 3025 <p>In cases where textual content is loaded before downloadable fonts are
jdaggett@2563 3026 available, user agents may render text as it would be rendered if
jdaggett@2563 3027 downloadable font resources are not available or they may render text
jdaggett@2563 3028 transparently with fallback fonts to avoid a flash of text using a
jdaggett@2563 3029 fallback font. In cases where the font download fails user agents must
jdaggett@2563 3030 display text, simply leaving transparent text is considered non-conformant
jdaggett@2563 3031 behavior. Authors are advised to use fallback fonts in their font lists
jdaggett@8431 3032 that closely match the metrics of the downloadable fonts to avoid large
jdaggett@8431 3033 page reflows where possible.
jdaggett@2563 3034
jdaggett@8863 3035 <p><a id=same-origin-restriction> </a><a
jdaggett@8863 3036 id=allowing-cross-origin-font-loading> </a>
jdaggett@8863 3037
jdaggett@8863 3038 <h3 id=font-fetching-requirements><span class=secno>4.9 </span>Font
jdaggett@8863 3039 fetching requirements</h3>
jdaggett@7253 3040 <!-- TPAC 2011 Resolution to require same-origin restriction for loading fonts:
jdaggett@7253 3041 http://lists.w3.org/Archives/Public/www-style/2011Nov/0711.html
jdaggett@7253 3042 http://www.w3.org/2011/10/31-webapps-minutes.html#item02
jdaggett@7253 3043 -->
jdaggett@2740 3044
jdaggett@8640 3045 <p>For font loads, user agents must use the <a
jdaggett@8640 3046 href="http://www.w3.org/TR/html5/infrastructure.html#cors-enabled-fetch">potentially
jdaggett@8640 3047 CORS-enabled fetch</a> method defined by the <a href="#HTML5"
jdaggett@8640 3048 rel=biblioentry>[HTML5]<!--{{!HTML5}}--></a> specification for URL's
jdaggett@8640 3049 defined within @font-face rules. When fetching, user agents must use
jdaggett@8640 3050 "Anonymous" mode, set the referrer source to the stylesheet's URL and set
jdaggett@8640 3051 the origin to the URL of the containing document.
jdaggett@2737 3052
jdaggett@8863 3053 <p class=note>The implications of this for authors are that fonts will
jdaggett@8863 3054 typically not be loaded cross-origin unless authors specifically takes
jdaggett@8863 3055 steps to permit cross-origin loads. Sites can explicitly allow cross-site
jdaggett@8863 3056 loading of font data using the <code>Access-Control-Allow-Origin</code>
jdaggett@8863 3057 HTTP header. For other schemes, no explicit mechanism to allow
jdaggett@8864 3058 cross-origin loading, beyond what is permitted by the <a
jdaggett@8863 3059 href="http://www.w3.org/TR/html5/infrastructure.html#cors-enabled-fetch">potentially
jdaggett@8864 3060 CORS-enabled fetch</a> method, is defined or required.
jdaggett@8863 3061
jdaggett@8872 3062 <div class=example> For the examples given below, assume that a document is
jdaggett@8872 3063 located at <code>http://example.com/page.html</code> and all URL's link to
jdaggett@8872 3064 valid font resources supported by the user agent. Fonts defined with the
jdaggett@8872 3065 ‘<a href="#descdef-src"><code class=property>src</code></a>’
jdaggett@8872 3066 descriptor values below will be loaded:
jdaggett@8872 3067 <pre>/* same origin (i.e. domain, scheme, port match document) */
jdaggett@8872 3068 src: url(fonts/simple.woff);
jdaggett@8872 3069 src: url(//fonts/simple.woff);
jdaggett@8872 3070
jdaggett@8872 3071 /* data url's with no redirects are treated as same origin */
jdaggett@8872 3072 src: url("data:application/font-woff;base64,...");
jdaggett@8872 3073
jdaggett@8872 3074 /* cross origin, different domain */
jdaggett@8872 3075 /* Access-Control-Allow-Origin response header set to '*' */
jdaggett@8872 3076 src: url(http://another.example.com/fonts/simple.woff);
jdaggett@8872 3077 </pre>
jdaggett@8872 3078 Fonts defined with the ‘<a href="#descdef-src"><code
jdaggett@8872 3079 class=property>src</code></a>’ descriptor values below will fail to
jdaggett@8872 3080 load:
jdaggett@8872 3081 <pre>/* cross origin, different scheme */
jdaggett@8872 3082 /* no Access-Control-xxx headers in response */
jdaggett@8872 3083 src: url(https://example.com/fonts/simple.woff);
jdaggett@8872 3084
jdaggett@8872 3085 /* cross origin, different domain */
jdaggett@8872 3086 /* no Access-Control-xxx headers in response */
jdaggett@8872 3087 src: url(http://another.example.com/fonts/simple.woff);
jdaggett@8872 3088 </pre>
jdaggett@8872 3089 </div>
jdaggett@8872 3090
jdaggett@6699 3091 <h2 id=font-matching-algorithm><span class=secno>5 </span>Font Matching
jdaggett@6699 3092 Algorithm</h2>
jdaggett@484 3093
jdaggett@2457 3094 <p>The algorithm below describes how fonts are associated with individual
jdaggett@2457 3095 runs of text. For each character in the run a font family is chosen and a
jdaggett@2457 3096 particular font face is selected containing a glyph for that character.
jdaggett@2457 3097
jdaggett@7309 3098 <h3 id=font-family-casing><span class=secno>5.1 </span>Case sensitivity of
jdaggett@7309 3099 font family names</h3>
jdaggett@7309 3100
jdaggett@7309 3101 <p>As part of the font matching algorithm outlined below, user agents must
jdaggett@7309 3102 match font family names used in style rules with actual font family names
jdaggett@8391 3103 contained in fonts available in a given environment or with font family
jdaggett@8391 3104 names defined in <a href="#at-font-face-rule"><code>@font-face</code></a>
jdaggett@8391 3105 rules. User agents must match these names case insensitively, using the
jdaggett@8391 3106 "Default Caseless Matching" algorithm outlined in the Unicode
jdaggett@8391 3107 specification <a href="#UNICODE6"
jdaggett@8391 3108 rel=biblioentry>[UNICODE6]<!--{{!UNICODE6}}--></a>. This algorithm is
jdaggett@8391 3109 detailed in section 3.13 entitled "Default Case Algorithms". Specifically,
jdaggett@8391 3110 the algorithm must be applied without normalizing the strings involved and
jdaggett@8391 3111 without applying any language-specific tailorings. The case folding method
jdaggett@8391 3112 specified by this algorithm uses the case mappings with status field
jdaggett@8391 3113 ‘<code class=property>C</code>’ or ‘<code class=property>F</code>’
jdaggett@8391 3114 in the CaseFolding.txt file of the Unicode Character Database.
jdaggett@7355 3115
jdaggett@7355 3116 <p class=note> For authors this means that font family names are matched
jdaggett@8272 3117 case insensitively, whether those names exist in a platform font or in the
jdaggett@8311 3118 <a href="#at-font-face-rule"><code>@font-face</code></a> rules contained
jdaggett@8311 3119 in a stylesheet. Authors should take care to ensure that names use a
jdaggett@8311 3120 character sequence consistent with the actual font family name,
jdaggett@8311 3121 particularly when using combining characters such as diacritical marks.
jdaggett@8311 3122 For example, a family name that contains an uppercase A (U+0041) followed
jdaggett@8311 3123 by a combining ring (U+030A) will <strong>not</strong> match a name that
jdaggett@8311 3124 looks identical but which uses the precomposed lowercase a-ring character
jdaggett@8311 3125 (U+00E5) instead of the combining sequence.
jdaggett@7309 3126
jdaggett@8391 3127 <p class=note> Implementors should take care to verify that a given
jdaggett@8391 3128 caseless string comparison implementation uses this precise algorithm and
jdaggett@8391 3129 not assume that a given platform string matching routine follows it, as
jdaggett@8391 3130 many of these have locale-specific behavior or use some level of string
jdaggett@8391 3131 normalization.
jdaggett@8391 3132
jdaggett@7309 3133 <h3 id=font-style-matching><span class=secno>5.2 </span>Matching font
jdaggett@2457 3134 styles</h3>
jdaggett@2457 3135
jdaggett@8391 3136 <p>The procedure for choosing a font for a given character in a run of text
jdaggett@8391 3137 consists of iterating over the font families named by the <a
jdaggett@8391 3138 href="#propdef-font-family" title="font-family!!property">‘<code
jdaggett@8391 3139 class=property>font-family</code>’</a> property, selecting a font face
jdaggett@531 3140 with the appropriate style based on other font properties and then
jdaggett@8391 3141 determining whether a glyph exists for the given character. This is done
jdaggett@7311 3142 using the <dfn id=character-map>character map</dfn> of the font, data
jdaggett@8397 3143 which maps characters to the default glyph for that character. A font is
jdaggett@8397 3144 considered to <dfn id=support>support</dfn> a given character if (1) the
jdaggett@8397 3145 character is contained in the font's <a
jdaggett@8397 3146 href="#character-map"><em>character map</em></a> and (2) if required by
jdaggett@8397 3147 the containing script, shaping information is available for that
jdaggett@8397 3148 character.
jdaggett@8397 3149
jdaggett@8397 3150 <p>Some legacy fonts may include a given character in the <a
jdaggett@8397 3151 href="#character-map"><em>character map</em></a> but lack the shaping
jdaggett@8397 3152 information (e.g. <a
jdaggett@8397 3153 href="http://www.microsoft.com/typography/otspec/ttochap1.htm">OpenType
jdaggett@8397 3154 layout tables</a> or <a
jdaggett@8397 3155 href="http://scripts.sil.org/cms/scripts/page.php?site_id=projects&amp;item_id=graphite_techAbout">Graphite
jdaggett@8397 3156 tables</a>) necessary for correctly rendering text runs containing that
jdaggett@8397 3157 character.
jdaggett@8397 3158
jdaggett@8397 3159 <p>Codepoint sequences consisting of a base character followed by a
jdaggett@8397 3160 sequence of combining characters are treated slightly differently, see the
jdaggett@8397 3161 section on <a href="#cluster-matching">cluster matching</a> below.
jdaggett@531 3162
jdaggett@7232 3163 <p>For this procedure, the <dfn id=default-face>default face</dfn> for a
jdaggett@7232 3164 given font family is defined to be the face that would be selected if all
jdaggett@7232 3165 font style properties were set to their initial value.
jdaggett@7232 3166
jdaggett@531 3167 <ol id=fontmatchingalg>
jdaggett@2457 3168 <li>Using the computed font property values for a given element, the user
jdaggett@8391 3169 agent starts with the first family name specified by the <a
jdaggett@8391 3170 href="#propdef-font-family" title="font-family!!property">‘<code
jdaggett@8278 3171 class=property>font-family</code>’</a> property.
jdaggett@2457 3172
jdaggett@8391 3173 <li>If the family name is a generic family keyword, the user agent looks
jdaggett@8391 3174 up the appropriate font family name to be used. User agents may choose
jdaggett@8391 3175 the generic font family to use based on the language of the containing
jdaggett@8391 3176 element or the Unicode range of the character.
jdaggett@2457 3177
jdaggett@2457 3178 <li>For other family names, the user agent attempts to find the family
jdaggett@8311 3179 name among fonts defined via <a
jdaggett@8311 3180 href="#at-font-face-rule"><code>@font-face</code></a> rules and then
jdaggett@8391 3181 among available system fonts, matching names with a <a
jdaggett@8391 3182 href="#font-family-casing">case-insensitive comparison</a> as outlined in
jdaggett@8391 3183 the section above. On systems containing fonts with multiple localized
jdaggett@8391 3184 font family names, user agents must match any of these names independent
jdaggett@8391 3185 of the underlying system locale or platform API used. If the font
jdaggett@8391 3186 resources defined for a given face in an <a
jdaggett@8311 3187 href="#at-font-face-rule"><code>@font-face</code></a> rule are either not
jdaggett@8311 3188 available or contain invalid font data, then the face should be treated
jdaggett@8311 3189 as not present in the family. If no faces are present for a family
jdaggett@8311 3190 defined via <a href="#at-font-face-rule"><code>@font-face</code></a>
jdaggett@8311 3191 rules, the family should be treated as missing; matching a platform font
jdaggett@8311 3192 with the same name must not occur in this case.
jdaggett@2457 3193
jdaggett@2457 3194 <li>If a font family match occurs, the user agent assembles the set of
jdaggett@6701 3195 font faces in that family and then narrows the set to a single face using
jdaggett@8391 3196 other font properties in the order given below. A group of faces defined
jdaggett@8391 3197 via <a href="#at-font-face-rule"><code>@font-face</code></a> rules with
jdaggett@8391 3198 identical font descriptor values but differing ‘<a
jdaggett@8391 3199 href="#descdef-unicode-range"><code
jdaggett@8391 3200 class=property>unicode-range</code></a>’ values are considered to be a
jdaggett@8391 3201 single <dfn id=composite-face>composite face</dfn> for this step:
jdaggett@2457 3202 <ol id=fontstylematchingalg>
jdaggett@8278 3203 <li><a href="#propdef-font-stretch"
jdaggett@8278 3204 title="font-stretch!!property">‘<code
jdaggett@8278 3205 class=property>font-stretch</code>’</a> is tried first. If the
jdaggett@8278 3206 matching set contains faces with width values matching the <a
jdaggett@8278 3207 href="#propdef-font-stretch" title="font-stretch!!property">‘<code
jdaggett@8278 3208 class=property>font-stretch</code>’</a> value, faces with other width
jdaggett@4624 3209 values are removed from the matching set. If there is no face that
jdaggett@4624 3210 exactly matches the width value the nearest width is used instead. If
jdaggett@8278 3211 the value of <a href="#propdef-font-stretch"
jdaggett@8278 3212 title="font-stretch!!property">‘<code
jdaggett@8368 3213 class=property>font-stretch</code>’</a> is <a
jdaggett@8368 3214 href="#font-stretch-normal-value" title="normal!!font-stretch">‘<code
jdaggett@8368 3215 class=property>normal</code>’</a> or one of the condensed values,
jdaggett@8278 3216 narrower width values are checked first, then wider values. If the
jdaggett@8278 3217 value of <a href="#propdef-font-stretch"
jdaggett@8278 3218 title="font-stretch!!property">‘<code
jdaggett@8278 3219 class=property>font-stretch</code>’</a> is one of the expanded
jdaggett@4624 3220 values, wider values are checked first, followed by narrower values.
jdaggett@4624 3221 Once the closest matching width has been determined by this process,
jdaggett@4624 3222 faces with other widths are removed from the matching set.
jdaggett@4624 3223
jdaggett@8278 3224 <li><a href="#propdef-font-style" title="font-style!!property">‘<code
jdaggett@8278 3225 class=property>font-style</code>’</a> is tried next. If the value of
jdaggett@8278 3226 <a href="#propdef-font-style" title="font-style!!property">‘<code
jdaggett@8278 3227 class=property>font-style</code>’</a> is ‘<a href="#italic"><code
jdaggett@8278 3228 class=property>italic</code></a>’, italic faces are checked first,
jdaggett@8278 3229 then oblique, then normal faces. If the value is ‘<a
jdaggett@8278 3230 href="#oblique"><code class=property>oblique</code></a>’, oblique
jdaggett@8278 3231 faces are checked first, then italic faces and then normal faces. If
jdaggett@8368 3232 the value is <a href="#font-style-normal-value"
jdaggett@8368 3233 title="normal!!font-style">‘<code
jdaggett@8368 3234 class=property>normal</code>’</a>, normal faces are checked first,
jdaggett@8279 3235 then oblique faces, then italic faces. Faces with other style values
jdaggett@8279 3236 are excluded from the matching set. User agents are permitted to
jdaggett@8279 3237 distinguish between italic and oblique faces within platform font
jdaggett@8391 3238 families but this is not required, so all italic or oblique faces may
jdaggett@8391 3239 be treated as italic faces. However, within font families defined via
jdaggett@8391 3240 <a href="#at-font-face-rule"><code>@font-face</code></a> rules, italic
jdaggett@8391 3241 and oblique faces must be distinguished using the value of the <a
jdaggett@8311 3242 href="#descdef-font-style" title="font-style!!descriptor">‘<code
jdaggett@8391 3243 class=property>font-style</code>’</a> descriptor. For families that
jdaggett@8391 3244 lack any italic or oblique faces, users agents may create artificial
jdaggett@8391 3245 oblique faces, if this is permitted by the value of the ‘<a
jdaggett@8391 3246 href="#propdef-font-synthesis"><code
jdaggett@8391 3247 class=property>font-synthesis</code></a>’ property.
jdaggett@8278 3248
jdaggett@8278 3249 <li><a href="#propdef-font-weight"
jdaggett@8278 3250 title="font-weight!!property">‘<code
jdaggett@8391 3251 class=property>font-weight</code>’</a> is matched next, so it will
jdaggett@8278 3252 always reduce the matching set to a single font face. If bolder/lighter
jdaggett@8278 3253 relative weights are used, the effective weight is calculated based on
jdaggett@8278 3254 the inherited weight value, as described in the definition of the <a
jdaggett@8278 3255 href="#propdef-font-weight" title="font-weight!!property">‘<code
jdaggett@8278 3256 class=property>font-weight</code>’</a> property. Given the desired
jdaggett@4624 3257 weight and the weights of faces in the matching set after the steps
jdaggett@4624 3258 above, if the desired weight is available that face matches. Otherwise,
jdaggett@4624 3259 a weight is chosen using the rules below:
jdaggett@531 3260 <ul>
jdaggett@531 3261 <li>If the desired weight is less than 400, weights below the desired
jdaggett@531 3262 weight are checked in descending order followed by weights above the
jdaggett@531 3263 desired weight in ascending order until a match is found.
jdaggett@531 3264
jdaggett@531 3265 <li>If the desired weight is greater than 500, weights above the
jdaggett@531 3266 desired weight are checked in ascending order followed by weights
jdaggett@531 3267 below the desired weight in descending order until a match is found.
jdaggett@531 3268
jdaggett@531 3269 <li>If the desired weight is 400, 500 is checked first and then the
jdaggett@531 3270 rule for desired weights less than 400 is used.
jdaggett@531 3271
jdaggett@531 3272 <li>If the desired weight is 500, 400 is checked first and then the
jdaggett@532 3273 rule for desired weights less than 400 is used.
jdaggett@531 3274 </ul>
jdaggett@531 3275
jdaggett@4624 3276 <li><span class=property>‘<a href="#propdef-font-size"><code
jdaggett@4624 3277 class=property>font-size</code></a>’</span> must be matched within a
jdaggett@4624 3278 UA-dependent margin of tolerance. (Typically, sizes for scalable fonts
jdaggett@4624 3279 are rounded to the nearest whole pixel, while the tolerance for
jdaggett@4624 3280 bitmapped fonts could be as large as 20%.) Further computations, e.g.,
jdaggett@4624 3281 by ‘<code class=property>em</code>’ values in other properties, are
jdaggett@4624 3282 based on the <span class=property>‘<a href="#propdef-font-size"><code
jdaggett@4624 3283 class=property>font-size</code></a>’</span> value that is used, not
jdaggett@4624 3284 the one that is specified.
jdaggett@531 3285 </ol>
jdaggett@531 3286
jdaggett@7232 3287 <li>
jdaggett@8391 3288 <p>If the matched face is defined via <a
jdaggett@8391 3289 href="#at-font-face-rule"><code>@font-face</code></a> rules, user agents
jdaggett@8391 3290 must use the procedure below to select a single font:
jdaggett@8391 3291
jdaggett@8391 3292 <ol>
jdaggett@8391 3293 <li>If the font resource has not been loaded and the range of characters
jdaggett@8391 3294 defined by the ‘<a href="#descdef-unicode-range"><code
jdaggett@8391 3295 class=property>unicode-range</code></a>’ descriptor value includes
jdaggett@8391 3296 the character in question, load the font.
jdaggett@8391 3297
jdaggett@8391 3298 <li>After downloading, if the <a
jdaggett@8391 3299 href="#effective-character-map"><em>effective character map</em></a>
jdaggett@8391 3300 supports the character in question, select that font.
jdaggett@8391 3301 </ol>
jdaggett@8391 3302
jdaggett@8391 3303 <p>When the matched face is a <a href="#composite-face"><em>composite
jdaggett@8391 3304 face</em></a>, user agents must use the procedure above on each of the
jdaggett@8391 3305 faces in the <a href="#composite-face"><em>composite face</em></a> in
jdaggett@8391 3306 reverse order of <a
jdaggett@8391 3307 href="#at-font-face-rule"><code>@font-face</code></a> rule definition.</p>
jdaggett@8391 3308
jdaggett@8391 3309 <p>While the download occurs, user agents may either wait until the font
jdaggett@8391 3310 is downloaded or render once with substituted font metrics and render
jdaggett@8391 3311 again once the font is downloaded.</p>
jdaggett@8391 3312
jdaggett@8391 3313 <li>
jdaggett@7232 3314 <p>If no matching face exists or the matched face does not contain a
jdaggett@7232 3315 glyph for the character to be rendered, the next family name is selected
jdaggett@8391 3316 and the previous three steps repeated. Glyphs from other faces in the
jdaggett@7232 3317 family are not considered. The only exception is that user agents may
jdaggett@8391 3318 optionally substitute a synthetically obliqued version of the <a
jdaggett@7232 3319 href="#default-face"><em>default face</em></a> if that face supports a
jdaggett@8391 3320 given glyph and synthesis of these faces is permitted by the value of
jdaggett@8391 3321 the ‘<a href="#propdef-font-synthesis"><code
jdaggett@8391 3322 class=property>font-synthesis</code></a>’ property. For example, a
jdaggett@8391 3323 synthetic italic version of the regular face may be used if the italic
jdaggett@8391 3324 face doesn't support glyphs for Arabic.</p>
jdaggett@7242 3325 <!-- resolution on the above: http://lists.w3.org/Archives/Public/www-style/2012Nov/0292.html -->
jdaggett@7242 3326
jdaggett@531 3327
jdaggett@531 3328 <li>If there are no more font families to be evaluated and no matching
jdaggett@8363 3329 face has been found, then the user agent performs a <dfn
jdaggett@8363 3330 id=system-font-fallback>system font fallback</dfn> procedure to find the
jdaggett@8363 3331 best match for the character to be rendered. The result of this procedure
jdaggett@8363 3332 may vary across user agents.
jdaggett@531 3333
jdaggett@531 3334 <li>If a particular character cannot be displayed using any font, the user
jdaggett@531 3335 agent should indicate by some means that a character is not being
jdaggett@2457 3336 displayed, displaying either a symbolic representation of the missing
jdaggett@2457 3337 glyph (e.g. using a <a
jdaggett@2457 3338 href="http://en.wikipedia.org/wiki/Last_resort_font">Last Resort
jdaggett@2457 3339 Font</a>) or using the missing character glyph from a default font.
jdaggett@512 3340 </ol>
jdaggett@2457 3341
jdaggett@8430 3342 <p>Optimizations of this process are allowed provided that an
jdaggett@8430 3343 implementation behaves as if the algorithm had been followed exactly.
jdaggett@8430 3344 Matching occurs in a well-defined order to insure that the results are as
jdaggett@8430 3345 consistent as possible across user agents, given an identical set of
jdaggett@8430 3346 available fonts and rendering technology.
jdaggett@8430 3347
jdaggett@8431 3348 <p>The <dfn id=first-available-font>first available font</dfn>, used in the
jdaggett@8431 3349 definition of <a
jdaggett@8431 3350 href="http://www.w3.org/TR/css3-values/#font-relative-lengths"><em>font-relative
jdaggett@8431 3351 lengths</em></a> such as ‘<code class=property>ex</code>’ and ‘<code
jdaggett@8431 3352 class=property>ch</code>’, is defined to be the first available font
jdaggett@8431 3353 that would match any character given font families in the ‘<code
jdaggett@8431 3354 class=property>font-family</code>’ list (or a user agent's default font
jdaggett@8431 3355 if none are available).
jdaggett@8431 3356
jdaggett@7309 3357 <h3 id=cluster-matching><span class=secno>5.3 </span>Cluster matching</h3>
jdaggett@6701 3358
jdaggett@8397 3359 <p>When text contains characters such as combining marks, ideally the base
jdaggett@8397 3360 character should be rendered using the same font as the mark, this assures
jdaggett@8397 3361 proper placement of the mark. For this reason, the font matching algorithm
jdaggett@8397 3362 for clusters is more specialized than the general case of matching a
jdaggett@8397 3363 single character by itself. For sequences containing variation selectors,
jdaggett@8397 3364 which indicate the precise glyph to be used for a given character, user
jdaggett@8397 3365 agents always attempt <a href="#system-font-fallback"><em>system font
jdaggett@8397 3366 fallback</em></a> to find the appropriate glyph before using the default
jdaggett@8397 3367 glyph of the base character.
jdaggett@8397 3368
jdaggett@8397 3369 <p>A sequence of codepoints containing combining mark or other modifiers is
jdaggett@8397 3370 termed a grapheme cluster (see <a href="#CSS3TEXT"
jdaggett@6701 3371 rel=biblioentry>[CSS3TEXT]<!--{{CSS3TEXT}}--></a> for a more complete
jdaggett@6701 3372 description). For a given cluster containing a base character, <em>b</em>
jdaggett@6701 3373 and a sequence of combining characters <em>c1, c2…</em>, the entire
jdaggett@6701 3374 cluster is matched using these steps:
jdaggett@6701 3375
jdaggett@6701 3376 <ol>
jdaggett@6701 3377 <li>For each family in the font list, a face is chosen using the style
jdaggett@6701 3378 selection rules defined in the previous section.
jdaggett@6701 3379 <ol>
jdaggett@7020 3380 <li>If all characters in the sequence <em>b + c1 + c2 …</em> are
jdaggett@7021 3381 completely supported by the font, select this font for the sequence.
jdaggett@6701 3382
jdaggett@6701 3383 <li>If a sequence of multiple codepoints is canonically equivalent to a
jdaggett@8397 3384 single character and the font <a href="#support"><em
jdaggett@8397 3385 title=support>supports</em></a> that character, select this font for
jdaggett@8397 3386 the sequence.
jdaggett@6701 3387 </ol>
jdaggett@6701 3388
jdaggett@6701 3389 <li>If no font was found in the font list in step 1:
jdaggett@6701 3390 <ol>
jdaggett@6701 3391 <li>If <em>c1</em> is a variation selector, system fallback must be used
jdaggett@8397 3392 to find a font that <a href="#support"><em
jdaggett@8397 3393 title=support>supports</em></a> the full sequence of <em>b + c1</em>.
jdaggett@8397 3394 If no font on the system <a href="#support"><em
jdaggett@8397 3395 title=support>supports</em></a> the full sequence, match the single
jdaggett@6701 3396 character <em>b</em> using the normal procedure for matching single
jdaggett@6701 3397 characters and ignore the variation selector. Note: a sequence with
jdaggett@8397 3398 more than one variation selector must be treated as an encoding error
jdaggett@8397 3399 and the trailing selectors must be ignored. <a href="#UNICODE6"
jdaggett@8397 3400 rel=biblioentry>[UNICODE6]<!--{{!UNICODE6}}--></a>
jdaggett@6701 3401
jdaggett@6701 3402 <li>Otherwise, the user agent may optionally use system font fallback to
jdaggett@8397 3403 match a font that <a href="#support"><em
jdaggett@8397 3404 title=support>supports</em></a> the entire cluster.
jdaggett@6701 3405 </ol>
jdaggett@6701 3406
jdaggett@6701 3407 <li>If no font is found in step 2, use the matching sequence from step 1
jdaggett@8397 3408 to determine the longest sequence that is completely <a
jdaggett@8397 3409 href="#support"><em title=support>supported</em></a> by a font in the
jdaggett@8397 3410 font list and attempt to match the remaining combining characters
jdaggett@6701 3411 separately using the rules for single characters.
jdaggett@6701 3412 </ol>
jdaggett@6701 3413
jdaggett@7309 3414 <h3 id=char-handling-issues><span class=secno>5.4 </span>Character handling
jdaggett@2457 3415 issues</h3>
jdaggett@2457 3416
jdaggett@8430 3417 <p>CSS font matching is always performed on text runs containing Unicode
jdaggett@8430 3418 characters, so documents using legacy encodings are assumed to have been
jdaggett@7311 3419 transcoded before matching fonts. For fonts containing <a
jdaggett@7311 3420 href="#character-map"><em title="character map">character maps</em></a>
jdaggett@7311 3421 for both legacy encodings and Unicode, the contents of the legacy encoding
jdaggett@7311 3422 <a href="#character-map"><em>character map</em></a> must have no effect on
jdaggett@7311 3423 the results of the font matching process.
jdaggett@2461 3424
jdaggett@2461 3425 <p>The font matching process does not assume that text runs are in either
jdaggett@2461 3426 normalized or denormalized form (see <a href="#CHARMOD-NORM"
jdaggett@3042 3427 rel=biblioentry>[CHARMOD-NORM]<!--{{CHARMOD-NORM}}--></a> for more
jdaggett@8430 3428 details). Fonts may only support precomposed forms and not the decomposed
jdaggett@8430 3429 sequence of base character plus combining marks. Authors should always
jdaggett@6701 3430 tailor their choice of fonts to their content, including whether that
jdaggett@6701 3431 content contains normalized or denormalized character streams.
jdaggett@2457 3432
jdaggett@8430 3433 <p>If a given character is a Private-Use Area Unicode codepoint, user
jdaggett@8430 3434 agents must only match font families named in the ‘<code
jdaggett@8430 3435 class=property>font-family</code>’ list that are not generic families.
jdaggett@8430 3436 If none of the families named in the ‘<code
jdaggett@8430 3437 class=property>font-family</code>’ list contain a glyph for that
jdaggett@8430 3438 codepoint, user agents must display some form of missing glyph symbol for
jdaggett@8430 3439 that character rather than attempting <a
jdaggett@8430 3440 href="#system-font-fallback"><em>system font fallback</em></a> for that
jdaggett@8430 3441 codepoint. When matching the replacement character U+FFFD, user agents may
jdaggett@8430 3442 skip the font matching process and immediately display some form of
jdaggett@8430 3443 missing glyph symbol, they are not required to display the glyph from the
jdaggett@8430 3444 font that would be selected by the font matching process.
jdaggett@2457 3445
jdaggett@2457 3446 <p>In general, the fonts for a given family will all have the same or
jdaggett@7311 3447 similar <a href="#character-map"><em title="character map">character
jdaggett@7311 3448 maps</em></a>. The process outlined here is designed to handle even font
jdaggett@7311 3449 families containing faces with widely variant <a href="#character-map"><em
jdaggett@7311 3450 title="character map">character maps</em></a>. However, authors are
jdaggett@7311 3451 cautioned that the use of such families can lead to unexpected results.
jdaggett@2457 3452
jdaggett@7309 3453 <h3 id=font-matching-changes><span class=secno>5.5 </span>Font matching
jdaggett@2509 3454 changes since CSS 2.1</h3>
jdaggett@2509 3455
jdaggett@2509 3456 <p>The algorithm above is different from CSS 2.1 in a number of key places.
jdaggett@2509 3457 These changes were made to better reflect actual font matching behavior
jdaggett@2509 3458 across user agent implementations.
jdaggett@2509 3459
jdaggett@2509 3460 <p>Differences compared to the font matching algorithm in CSS 2.1:
jdaggett@2509 3461
jdaggett@2509 3462 <ul>
jdaggett@2509 3463 <li>The algorithm includes font-stretch matching.
jdaggett@2509 3464
jdaggett@2509 3465 <li>All possible font-style matching scenarios are delineated.
jdaggett@2509 3466
jdaggett@2509 3467 <li>Small-caps fonts are not matched as part of the font matching process,
jdaggett@2509 3468 they are now handled via font features.
jdaggett@2509 3469
jdaggett@2509 3470 <li>Unicode variation selector matching is required.
jdaggett@6701 3471
jdaggett@6701 3472 <li>Cluster sequences are matched as a unit.
jdaggett@2509 3473 </ul>
jdaggett@531 3474
jdaggett@7309 3475 <h3 id=font-matching-examples><span class=secno>5.6 </span>Font matching
jdaggett@6701 3476 examples</h3>
jdaggett@6701 3477
jdaggett@531 3478 <div class=example>
jdaggett@531 3479 <p>It's useful to note that the CSS selector syntax may be used to create
jdaggett@531 3480 language-sensitive typography. For example, some Chinese and Japanese
jdaggett@1149 3481 characters are unified to have the same Unicode code point, although the
jdaggett@890 3482 abstract glyphs are not the same in the two languages.
jdaggett@531 3483
jdaggett@531 3484 <pre>*:lang(ja-jp) { font: 900 14pt/16pt &quot;Heisei Mincho W9&quot;, serif; }
jdaggett@531 3485 *:lang(zh-tw) { font: 800 14pt/16.5pt &quot;Li Sung&quot;, serif; }
jdaggett@512 3486 </pre>
jdaggett@531 3487
jdaggett@8430 3488 <p>This selects any element that has the given language — Japanese or
jdaggett@8430 3489 Traditional Chinese — and uses the appropriate font.
jdaggett@512 3490 </div>
jdaggett@1662 3491
jdaggett@6699 3492 <h2 id=font-rend-props><span class=secno>6 </span>Font Feature Properties</h2>
jdaggett@1662 3493
jdaggett@1856 3494 <p>Modern font technologies support a variety of advanced typographic and
jdaggett@1856 3495 language-specific font features. Using these features, a single font can
jdaggett@1856 3496 provide glyphs for a wide range of ligatures, contextual and stylistic
jdaggett@1856 3497 alternates, tabular and old-style figures, small capitals, automatic
jdaggett@1856 3498 fractions, swashes, and alternates specific to a given language. To allow
jdaggett@8313 3499 authors control over these font capabilities, the ‘<code
jdaggett@8313 3500 class=property>font-variant</code>’ property has been expanded for CSS3.
jdaggett@8313 3501 It now functions as a shorthand for a set of properties that provide
jdaggett@8313 3502 control over stylistic font features.
jdaggett@1856 3503
jdaggett@1856 3504 <h3 id=glyph-selection-positioning><span class=secno>6.1 </span>Glyph
jdaggett@1856 3505 selection and positioning</h3>
jdaggett@1856 3506
jdaggett@1856 3507 <p>Simple fonts used for displaying Latin text use a very basic processing
jdaggett@8313 3508 model. Fonts contain a <a href="#character-map"><em>character map</em></a>
jdaggett@8313 3509 which maps each character to a glyph for that character. Glyphs for
jdaggett@8313 3510 subsequent characters are simply placed one after the other along a run of
jdaggett@8313 3511 text. Modern font formats such as OpenType and AAT (Apple Advanced
jdaggett@8313 3512 Typography) use a richer processing model. The glyph for a given character
jdaggett@8313 3513 can be chosen and positioned not just based on the codepoint of the
jdaggett@8313 3514 character itself, but also on adjacent characters as well as the language,
jdaggett@8313 3515 script, and features enabled for the text. Font features may be required
jdaggett@8313 3516 for specific scripts, or recommended as enabled by default or they might
jdaggett@8313 3517 be stylistic features meant to be used under author control.
jdaggett@1856 3518
jdaggett@1856 3519 <p>For a good visual overview of these features, see the <a
jdaggett@1856 3520 href="#OPENTYPE-FONT-GUIDE"
jdaggett@1856 3521 rel=biblioentry>[OPENTYPE-FONT-GUIDE]<!--{{OPENTYPE-FONT-GUIDE}}--></a>.
jdaggett@1856 3522 For a detailed description of glyph processing for OpenType fonts, see <a
jdaggett@1856 3523 href="#WINDOWS-GLYPH-PROC"
jdaggett@1856 3524 rel=biblioentry>[WINDOWS-GLYPH-PROC]<!--{{WINDOWS-GLYPH-PROC}}--></a>.
jdaggett@1856 3525
jdaggett@8313 3526 <p>Stylistic font features can be classified into two broad categories:
jdaggett@6177 3527 ones that affect the harmonization of glyph shapes with the surrounding
jdaggett@8313 3528 context, such as kerning and ligature features, and ones such as the
jdaggett@6177 3529 small-caps, subscript/superscript and alternate features that affect shape
jdaggett@6177 3530 selection.
jdaggett@6176 3531
jdaggett@8313 3532 <p>The subproperties of <a href="#propdef-font-variant"
jdaggett@8313 3533 title="font-variant!!property">‘<code
jdaggett@8313 3534 class=property>font-variant</code>’</a> listed below are used to control
jdaggett@8313 3535 these stylistic font features. They do not control features that are
jdaggett@8313 3536 required for displaying certain scripts, such as the OpenType features
jdaggett@8313 3537 used when displaying Arabic or Indic language text. They affect glyph
jdaggett@8313 3538 selection and positioning, but do not affect font selection as described
jdaggett@8313 3539 in the font matching section (except in cases required for compatibility
jdaggett@8313 3540 with CSS 2.1).
jdaggett@1856 3541
jdaggett@1856 3542 <p>To assure consistent behavior across user agents, the equivalent
jdaggett@8313 3543 OpenType property settings are listed for individual properties and are
jdaggett@8313 3544 normative. When using other font formats these should be used as a
jdaggett@8313 3545 guideline to map CSS font feature property values to specific font
jdaggett@8313 3546 features.
jdaggett@1856 3547
jdaggett@1856 3548 <h3 id=language-specific-support><span class=secno>6.2
jdaggett@1856 3549 </span>Language-specific display</h3>
jdaggett@1856 3550
jdaggett@1856 3551 <p>OpenType also supports language-specific glyph selection and
jdaggett@1856 3552 positioning, so that text can be displayed correctly in cases where the
jdaggett@8313 3553 language dictates a specific display behavior. Many languages share a
jdaggett@8313 3554 common script, but the shape of certain letters can vary across those
jdaggett@8313 3555 languages. For example, certain Cyrillic letters have different shapes in
jdaggett@8313 3556 Russian text than in Bulgarian. In Latin text, it's common to render "fi"
jdaggett@8313 3557 with an explicit fi-ligature that lacks a dot on the "i". However, in
jdaggett@8313 3558 languages such as Turkish which uses both a dotted-i and a dotless-i, it's
jdaggett@8313 3559 important to not use this ligature or use a specialized version that
jdaggett@8313 3560 contains a dot over the "i". The example below shows language-specific
jdaggett@8313 3561 variations based on stylistic traditions found in Spanish, Italian and
jdaggett@8313 3562 French orthography:
jdaggett@2515 3563
jdaggett@2515 3564 <div class=featex><img alt="language specific forms, spanish"
jdaggett@2515 3565 src=locl-1.png></div>
jdaggett@2515 3566
jdaggett@2515 3567 <div class=featex><img alt="language specific forms, italian"
jdaggett@2515 3568 src=locl-2.png></div>
jdaggett@2515 3569
jdaggett@2515 3570 <div class=featex><img alt="language specific forms, french"
jdaggett@2515 3571 src=locl-3.png></div>
jdaggett@1856 3572
jdaggett@8313 3573 <p>If the content language of the element is known according to the rules
jdaggett@7355 3574 of the <a
jdaggett@7355 3575 href="http://www.w3.org/TR/CSS21/conform.html#doclanguage">document
jdaggett@7355 3576 language</a>, user agents are required to infer the OpenType language
jdaggett@7355 3577 system from the content language and use that when selecting and
jdaggett@7355 3578 positioning glyphs using an OpenType font.
jdaggett@7355 3579
jdaggett@7355 3580 <p>For OpenType fonts, in some cases it may be necessary to explicitly
jdaggett@7355 3581 declare the OpenType language to be used, for example when displaying text
jdaggett@7355 3582 in a given language that uses the typographic conventions of another
jdaggett@7355 3583 language or when the font does not explicitly support a given language but
jdaggett@7355 3584 supports a language that shares common typographic conventions. The ‘<a
jdaggett@4624 3585 href="#propdef-font-language-override"><code
jdaggett@4624 3586 class=property>font-language-override</code></a>’ property is used for
jdaggett@8225 3587 this purpose.</p>
jdaggett@1662 3588 <!-- prop: font-kerning -->
jdaggett@1662 3589
jdaggett@1856 3590 <h3 id=font-kerning-prop><span class=secno>6.3 </span>Kerning: the <a
jdaggett@1662 3591 href="#propdef-font-kerning">font-kerning</a> property</h3>
jdaggett@1662 3592
jdaggett@4624 3593 <table class=propdef id=namefont-kerningvalueauto-normal-noneini>
jdaggett@1662 3594 <tbody>
jdaggett@1662 3595 <tr>
jdaggett@1662 3596 <td>Name:
jdaggett@1662 3597
jdaggett@1662 3598 <td><dfn id=propdef-font-kerning>font-kerning</dfn>
jdaggett@1662 3599
jdaggett@1662 3600 <tr>
jdaggett@1662 3601 <td>Value:
jdaggett@1662 3602
jdaggett@8278 3603 <td><a href="#font-kerning-auto-value"
jdaggett@8278 3604 title="auto!!font-kerning">auto</a> | <a
jdaggett@8278 3605 href="#font-kerning-normal-value"
jdaggett@8278 3606 title="normal!!font-kerning">normal</a> | <a
jdaggett@8278 3607 href="#font-kerning-none-value" title="none!!font-kerning">none</a>
jdaggett@1662 3608
jdaggett@1662 3609 <tr>
jdaggett@1662 3610 <td>Initial:
jdaggett@1662 3611
jdaggett@1856 3612 <td>auto
jdaggett@1662 3613
jdaggett@1662 3614 <tr>
jdaggett@1662 3615 <td>Applies to:
jdaggett@1662 3616
jdaggett@1662 3617 <td>all elements
jdaggett@1662 3618
jdaggett@1662 3619 <tr>
jdaggett@1662 3620 <td>Inherited:
jdaggett@1662 3621
jdaggett@1662 3622 <td>yes
jdaggett@1662 3623
jdaggett@1662 3624 <tr>
jdaggett@1662 3625 <td>Percentages:
jdaggett@1662 3626
jdaggett@1662 3627 <td>N/A
jdaggett@1662 3628
jdaggett@1662 3629 <tr>
jdaggett@1662 3630 <td>Media:
jdaggett@1662 3631
jdaggett@1662 3632 <td>visual
jdaggett@1662 3633
jdaggett@1662 3634 <tr>
jdaggett@1662 3635 <td>Computed value:
jdaggett@1662 3636
jdaggett@1662 3637 <td>as specified
jdaggett@7377 3638
jdaggett@7377 3639 <tr>
jdaggett@7377 3640 <td>Animatable:
jdaggett@7377 3641
jdaggett@7377 3642 <td>no
jdaggett@1662 3643 </table>
jdaggett@1662 3644
jdaggett@2509 3645 <p>Kerning is the contextual adjustment of inter-glyph spacing. This
jdaggett@2509 3646 property controls metric kerning, kerning that utilizes adjustment data
jdaggett@8276 3647 contained in the font.
jdaggett@8276 3648
jdaggett@8276 3649 <dl>
jdaggett@8278 3650 <dt><dfn id=font-kerning-auto-value title="auto!!font-kerning">auto</dfn>
jdaggett@8276 3651
jdaggett@8276 3652 <dd>Specifies that kerning is applied at the discretion of the user agent
jdaggett@8276 3653
jdaggett@8278 3654 <dt><dfn id=font-kerning-normal-value
jdaggett@8278 3655 title="normal!!font-kerning">normal</dfn>
jdaggett@8276 3656
jdaggett@8276 3657 <dd>Specifies that kerning is applied
jdaggett@8276 3658
jdaggett@8278 3659 <dt><dfn id=font-kerning-none-value title="none!!font-kerning">none</dfn>
jdaggett@8276 3660
jdaggett@8276 3661 <dd>Specifies that kerning is not applied
jdaggett@8276 3662 </dl>
jdaggett@1662 3663
jdaggett@1662 3664 <p>For fonts that do not include kerning data this property will have no
jdaggett@1662 3665 visible effect. When rendering with OpenType fonts, the <a
jdaggett@1662 3666 href="#OPENTYPE" rel=biblioentry>[OPENTYPE]<!--{{!OPENTYPE}}--></a>
jdaggett@2515 3667 specification suggests that kerning be enabled by default. When kerning is
jdaggett@6436 3668 enabled, the OpenType <span class=tag>kern</span> feature is enabled (for
jdaggett@8276 3669 vertical text runs the <span class=tag>vkrn</span> feature is enabled
jdaggett@8276 3670 instead). User agents must also support fonts that only support kerning
jdaggett@8276 3671 via data contained in a <span class=tag>kern</span> font table, as
jdaggett@8276 3672 detailed in the OpenType specification. If the ‘<code
jdaggett@8276 3673 class=property>letter-spacing</code>’ property is defined, kerning
jdaggett@8276 3674 adjustments are considered part of the default spacing and letter spacing
jdaggett@8276 3675 adjustments are made after kerning has been applied.
jdaggett@8276 3676
jdaggett@8276 3677 <p>When set to ‘<code class=property>auto</code>’, user agents can
jdaggett@8276 3678 determine whether to apply kerning or not based on a number of factors:
jdaggett@8276 3679 text size, script, or other factors that influence text processing speed.
jdaggett@8368 3680 Authors who want proper kerning should use <a
jdaggett@8368 3681 href="#font-kerning-normal-value" title="normal!!font-kerning">‘<code
jdaggett@8368 3682 class=property>normal</code>’</a> to explicitly enable kerning.
jdaggett@8279 3683 Likewise, some authors may prefer to disable kerning in situations where
jdaggett@8279 3684 performance is more important than precise appearance. However, in
jdaggett@8279 3685 well-designed modern implementations the use of kerning generally does not
jdaggett@8279 3686 have a large impact on text rendering speed.</p>
jdaggett@6176 3687 <!-- prop: font-variant-ligatures -->
jdaggett@6176 3688
jdaggett@6176 3689 <h3 id=font-variant-ligatures-prop><span class=secno>6.4 </span>Ligatures:
jdaggett@6176 3690 the <a href="#propdef-font-variant-ligatures">font-variant-ligatures</a>
jdaggett@6176 3691 property</h3>
jdaggett@6176 3692
jdaggett@6436 3693 <table class=propdef id=namefont-variant-ligaturesvaluenormal-no>
jdaggett@6176 3694 <tbody>
jdaggett@6176 3695 <tr>
jdaggett@6176 3696 <td>Name:
jdaggett@6176 3697
jdaggett@6176 3698 <td><dfn id=propdef-font-variant-ligatures>font-variant-ligatures</dfn>
jdaggett@6176 3699
jdaggett@6176 3700 <tr>
jdaggett@6176 3701 <td>Value:
jdaggett@6176 3702
jdaggett@8278 3703 <td><a href="#font-variant-ligatures-normal-value"
jdaggett@8278 3704 title="normal!!font-variant-ligatures">normal</a> | <a
jdaggett@8278 3705 href="#font-variant-ligatures-none-value"
jdaggett@8278 3706 title="none!!font-variant-ligatures">none</a> | [ <a
jdaggett@8225 3707 href="#common-lig-values"><var>&lt;common-lig-values&gt;</var></a> ||
jdaggett@8225 3708 <a
jdaggett@8225 3709 href="#discretionary-lig-values"><var>&lt;discretionary-lig-values&gt;</var></a>
jdaggett@8225 3710 || <a
jdaggett@8225 3711 href="#historical-lig-values"><var>&lt;historical-lig-values&gt;</var></a>
jdaggett@8225 3712 || <a
jdaggett@8225 3713 href="#contextual-alt-values"><var>&lt;contextual-alt-values&gt;</var></a>
jdaggett@8225 3714 ]
jdaggett@6176 3715
jdaggett@6176 3716 <tr>
jdaggett@6176 3717 <td>Initial:
jdaggett@6176 3718
jdaggett@6176 3719 <td>normal
jdaggett@6176 3720
jdaggett@6176 3721 <tr>
jdaggett@6176 3722 <td>Applies to:
jdaggett@6176 3723
jdaggett@6176 3724 <td>all elements
jdaggett@6176 3725
jdaggett@6176 3726 <tr>
jdaggett@6176 3727 <td>Inherited:
jdaggett@6176 3728
jdaggett@6176 3729 <td>yes
jdaggett@6176 3730
jdaggett@6176 3731 <tr>
jdaggett@6176 3732 <td>Percentages:
jdaggett@6176 3733
jdaggett@6176 3734 <td>N/A
jdaggett@6176 3735
jdaggett@6176 3736 <tr>
jdaggett@6176 3737 <td>Media:
jdaggett@6176 3738
jdaggett@6176 3739 <td>visual
jdaggett@6176 3740
jdaggett@6176 3741 <tr>
jdaggett@6176 3742 <td>Computed value:
jdaggett@6176 3743
jdaggett@6176 3744 <td>as specified
jdaggett@7377 3745
jdaggett@7377 3746 <tr>
jdaggett@7377 3747 <td>Animatable:
jdaggett@7377 3748
jdaggett@7377 3749 <td>no
jdaggett@6176 3750 </table>
jdaggett@6176 3751
jdaggett@6436 3752 <p>Ligatures and contextual forms are ways of combining glyphs to produce
jdaggett@8276 3753 more harmonized forms.
jdaggett@6176 3754
jdaggett@6176 3755 <pre
jdaggett@8225 3756 class=prod><dfn id=common-lig-values><var>&lt;common-lig-values&gt;</var></dfn> = [ <a href="#common-ligatures">common-ligatures</a> | <a href="#no-common-ligatures">no-common-ligatures</a> ]</pre>
jdaggett@6176 3757
jdaggett@6176 3758 <pre
jdaggett@8225 3759 class=prod><dfn id=discretionary-lig-values><var>&lt;discretionary-lig-values&gt;</var></dfn> = [ <a href="#discretionary-ligatures">discretionary-ligatures</a> | <a href="#no-discretionary-ligatures">no-discretionary-ligatures</a> ]</pre>
jdaggett@6176 3760
jdaggett@6176 3761 <pre
jdaggett@8225 3762 class=prod><dfn id=historical-lig-values><var>&lt;historical-lig-values&gt;</var></dfn> = [ <a href="#historical-ligatures">historical-ligatures</a> | <a href="#no-historical-ligatures">no-historical-ligatures</a> ]</pre>
jdaggett@6176 3763
jdaggett@6176 3764 <pre
jdaggett@8225 3765 class=prod><dfn id=contextual-alt-values><var>&lt;contextual-alt-values&gt;</var></dfn> = [ <a href="#contextual">contextual</a> | <a href="#no-contextual">no-contextual</a> ]</pre>
jdaggett@6176 3766
jdaggett@6176 3767 <p>Individual values have the following meanings:
jdaggett@6176 3768
jdaggett@6176 3769 <dl>
jdaggett@8278 3770 <dt><dfn id=font-variant-ligatures-normal-value
jdaggett@8278 3771 title="normal!!font-variant-ligatures">normal</dfn>
jdaggett@8278 3772
jdaggett@8368 3773 <dd>A value of <a href="#font-variant-ligatures-normal-value"
jdaggett@8368 3774 title="normal!!font-variant-ligatures">‘<code
jdaggett@8368 3775 class=property>normal</code>’</a> specifies that common default
jdaggett@8279 3776 features are enabled, <a href="#font-feature-resolution">as described in
jdaggett@8279 3777 detail in the next section</a>. For OpenType fonts, common ligatures and
jdaggett@8279 3778 contextual forms are on by default, discretionary and historical
jdaggett@8279 3779 ligatures are not.
jdaggett@8278 3780
jdaggett@8278 3781 <dt><dfn id=font-variant-ligatures-none-value
jdaggett@8278 3782 title="none!!font-variant-ligatures">none</dfn>
jdaggett@8276 3783
jdaggett@8276 3784 <dd>Specifies that all types of ligatures and contextual forms covered by
jdaggett@8276 3785 this property are explicitly disabled. In situations where ligatures are
jdaggett@8276 3786 not considered necessary, this may improve the speed of text rendering.
jdaggett@8276 3787
jdaggett@6176 3788 <dt><dfn id=common-ligatures>common-ligatures</dfn>
jdaggett@6176 3789
jdaggett@6436 3790 <dd>Enables display of common ligatures (OpenType features: <span
jdaggett@6436 3791 class=tag>liga, clig</span>). For OpenType fonts, common ligatures are
jdaggett@6436 3792 enabled by default.
jdaggett@6176 3793 </dl>
jdaggett@6176 3794
jdaggett@6176 3795 <div class=featex><img alt="common ligature example" src=liga.png></div>
jdaggett@6176 3796
jdaggett@6176 3797 <dl>
jdaggett@6176 3798 <dt><dfn id=no-common-ligatures>no-common-ligatures</dfn>
jdaggett@6176 3799
jdaggett@6436 3800 <dd>Disables display of common ligatures (OpenType features: <span
jdaggett@6436 3801 class=tag>liga, clig</span>).
jdaggett@6176 3802
jdaggett@6176 3803 <dt><dfn id=discretionary-ligatures>discretionary-ligatures</dfn>
jdaggett@6176 3804
jdaggett@6436 3805 <dd>Enables display of discretionary ligatures (OpenType feature: <span
jdaggett@8277 3806 class=tag>dlig</span>). Which ligatures are discretionary or optional is
jdaggett@8277 3807 decided by the type designer, so authors will need to refer to the
jdaggett@6176 3808 documentation of a given font to understand which ligatures are
jdaggett@6176 3809 considered discretionary.
jdaggett@6176 3810 </dl>
jdaggett@6176 3811
jdaggett@6176 3812 <div class=featex><img alt="discretionary ligature example" src=dlig.png></div>
jdaggett@6176 3813
jdaggett@6176 3814 <dl>
jdaggett@6176 3815 <dt><dfn id=no-discretionary-ligatures>no-discretionary-ligatures</dfn>
jdaggett@6176 3816
jdaggett@6436 3817 <dd>Disables display of discretionary ligatures (OpenType feature: <span
jdaggett@6436 3818 class=tag>dlig</span>).
jdaggett@6176 3819
jdaggett@6176 3820 <dt><dfn id=historical-ligatures>historical-ligatures</dfn>
jdaggett@6176 3821
jdaggett@6436 3822 <dd>Enables display of historical ligatures (OpenType feature: <span
jdaggett@6436 3823 class=tag>hlig</span>).
jdaggett@6176 3824 </dl>
jdaggett@6176 3825
jdaggett@6176 3826 <div class=featex><img alt="historical ligature example" src=hlig.png></div>
jdaggett@6176 3827
jdaggett@6176 3828 <dl>
jdaggett@6176 3829 <dt><dfn id=no-historical-ligatures>no-historical-ligatures</dfn>
jdaggett@6176 3830
jdaggett@6436 3831 <dd>Disables display of historical ligatures (OpenType feature: <span
jdaggett@6436 3832 class=tag>hlig</span>).
jdaggett@6176 3833
jdaggett@6176 3834 <dt><dfn id=contextual>contextual</dfn>
jdaggett@6176 3835
jdaggett@6436 3836 <dd>Enables display of contextual alternates (OpenType feature: <span
jdaggett@6436 3837 class=tag>calt</span>). Although not strictly a ligature feature, like
jdaggett@6176 3838 ligatures this feature is commonly used to harmonize the shapes of glyphs
jdaggett@6436 3839 with the surrounding context. For OpenType fonts, this feature is on by
jdaggett@6436 3840 default.
jdaggett@6176 3841 </dl>
jdaggett@6176 3842
jdaggett@6176 3843 <div class=featex><img alt="contextual alternate example" src=calt.png></div>
jdaggett@6176 3844
jdaggett@6176 3845 <dl>
jdaggett@6176 3846 <dt><dfn id=no-contextual>no-contextual</dfn>
jdaggett@6176 3847
jdaggett@6436 3848 <dd>Disables display of contextual alternates (OpenType feature: <span
jdaggett@6436 3849 class=tag>calt</span>).
jdaggett@6176 3850 </dl>
jdaggett@6176 3851
jdaggett@6176 3852 <p>Required ligatures, needed for correctly rendering complex scripts, are
jdaggett@8278 3853 not affected by the settings above, including ‘<code
jdaggett@8278 3854 class=property>none</code>’ (OpenType feature: <span
jdaggett@6436 3855 class=tag>rlig</span>).</p>
jdaggett@3460 3856 <!-- prop: font-variant-position -->
jdaggett@3460 3857
jdaggett@6176 3858 <h3 id=font-variant-position-prop><span class=secno>6.5 </span>Subscript
jdaggett@3638 3859 and superscript forms: the <a
jdaggett@3460 3860 href="#propdef-font-variant-position">font-variant-position</a> property</h3>
jdaggett@3460 3861
jdaggett@4624 3862 <table class=propdef id=namefont-variant-positionvaluenormal-sub>
jdaggett@1662 3863 <tbody>
jdaggett@1662 3864 <tr>
jdaggett@1662 3865 <td>Name:
jdaggett@1662 3866
jdaggett@3460 3867 <td><dfn id=propdef-font-variant-position>font-variant-position</dfn>
jdaggett@1662 3868
jdaggett@1662 3869 <tr>
jdaggett@1662 3870 <td>Value:
jdaggett@1662 3871
jdaggett@8368 3872 <td><a href="#font-variant-position-normal-value"
jdaggett@8368 3873 title="normal!!font-variant-position">normal</a> | <a
jdaggett@8279 3874 href="#sub">sub</a> | <a href="#super">super</a>
jdaggett@1732 3875
jdaggett@1732 3876 <tr>
jdaggett@1732 3877 <td>Initial:
jdaggett@1732 3878
jdaggett@1732 3879 <td>normal
jdaggett@1732 3880
jdaggett@1732 3881 <tr>
jdaggett@1732 3882 <td>Applies to:
jdaggett@1732 3883
jdaggett@1732 3884 <td>all elements
jdaggett@1732 3885
jdaggett@1732 3886 <tr>
jdaggett@1732 3887 <td>Inherited:
jdaggett@1732 3888
jdaggett@1732 3889 <td>yes
jdaggett@1732 3890
jdaggett@1732 3891 <tr>
jdaggett@1732 3892 <td>Percentages:
jdaggett@1732 3893
jdaggett@1732 3894 <td>N/A
jdaggett@1732 3895
jdaggett@1732 3896 <tr>
jdaggett@1732 3897 <td>Media:
jdaggett@1732 3898
jdaggett@1732 3899 <td>visual
jdaggett@1732 3900
jdaggett@1732 3901 <tr>
jdaggett@1732 3902 <td>Computed value:
jdaggett@1732 3903
jdaggett@1732 3904 <td>as specified
jdaggett@7377 3905
jdaggett@7377 3906 <tr>
jdaggett@7377 3907 <td>Animatable:
jdaggett@7377 3908
jdaggett@7377 3909 <td>no
jdaggett@1732 3910 </table>
jdaggett@1732 3911
jdaggett@5890 3912 <p>This property is used to enable typographic subscript and superscript
jdaggett@5890 3913 glyphs. These are alternate glyphs designed within the same em-box as
jdaggett@5890 3914 default glyphs and are intended to be laid out on the same baseline as the
jdaggett@5890 3915 default glyphs, with no resizing or repositioning of the baseline. They
jdaggett@5890 3916 are explicitly designed to match the surrounding text and to be more
jdaggett@5890 3917 readable without affecting the line height.
jdaggett@3511 3918
jdaggett@3511 3919 <div class=figure><img alt="comparison between real subscript glyphs and
jdaggett@3511 3920 synthesized ones" src=realsubscripts.png>
jdaggett@3511 3921 <p class=caption>Subscript glyphs (top) vs. typical synthesized subscripts
jdaggett@3511 3922 (bottom)
jdaggett@3511 3923 </div>
jdaggett@3460 3924
jdaggett@8279 3925 <p>Individual values have the following meanings:
jdaggett@8279 3926
jdaggett@8279 3927 <dl>
jdaggett@8368 3928 <dt><dfn id=font-variant-position-normal-value
jdaggett@8368 3929 title="normal!!font-variant-position">normal</dfn>
jdaggett@8279 3930
jdaggett@8279 3931 <dd>None of the features listed below are enabled.
jdaggett@8279 3932
jdaggett@8279 3933 <dt><dfn id=sub>sub</dfn>
jdaggett@8279 3934
jdaggett@8279 3935 <dd>Enables display of subscript variants (OpenType feature: <span
jdaggett@8279 3936 class=tag>subs</span>).
jdaggett@8279 3937
jdaggett@8279 3938 <dt><dfn id=super>super</dfn>
jdaggett@8279 3939
jdaggett@8279 3940 <dd>Enables display of superscript variants (OpenType feature: <span
jdaggett@8279 3941 class=tag>sups</span>).
jdaggett@8279 3942 </dl>
jdaggett@5890 3943
jdaggett@5890 3944 <p>Because of the semantic nature of subscripts and superscripts, when the
jdaggett@8279 3945 value is either ‘<a href="#sub"><code class=property>sub</code></a>’
jdaggett@8279 3946 or ‘<a href="#super"><code class=property>super</code></a>’ for a
jdaggett@8279 3947 given contiguous run of text, if a variant glyph is not available for all
jdaggett@8279 3948 the characters in the run, simulated glyphs must be synthesized for all
jdaggett@8279 3949 characters using reduced forms of the glyphs that would be used without
jdaggett@8280 3950 this feature applied. This is done per run to avoid a mixture of variant
jdaggett@8280 3951 glyphs and synthesized ones that would not align correctly. In the case of
jdaggett@8280 3952 OpenType fonts that lack subscript or superscript glyphs for a given
jdaggett@8280 3953 character, user agents must use the appropriate subscript and superscript
jdaggett@8280 3954 metrics specified in the selected font's <a
jdaggett@3460 3955 href="http://www.microsoft.com/typography/otspec/os2.htm#subxs">OS/2
jdaggett@3460 3956 table</a> <a href="#OPENTYPE"
jdaggett@5891 3957 rel=biblioentry>[OPENTYPE]<!--{{!OPENTYPE}}--></a> to calculate the size
jdaggett@5891 3958 and offset of the synthesized substitutes.
jdaggett@2461 3959
jdaggett@8280 3960 <div class=figure><img alt="alternate superscripts vs. glyphs synthesized
jdaggett@8280 3961 using superscript metrics" src=superscript-alt-synth.png>
jdaggett@8280 3962 <p class=caption>Superscript alternate glyph (left), synthesized
jdaggett@8280 3963 superscript glyphs (middle), and incorrect mixture of the two (right)
jdaggett@8280 3964 </div>
jdaggett@8280 3965
jdaggett@8385 3966 <p>In situations where text decorations are only applied to runs of text
jdaggett@8385 3967 containing superscript or subscript glyphs, the synthesized glyphs must be
jdaggett@8385 3968 used to avoid problems with the placement of decorations.
jdaggett@8385 3969
jdaggett@2461 3970 <p>In the past, user agents have used font-size and vertical-align to
jdaggett@8368 3971 simulate subscripts and superscripts for the <code title="HTML sub
jdaggett@8368 3972 element">sub</code> and <code title="HTML sup element">sup</code>
jdaggett@8368 3973 elements. To allow a backwards compatible way of defining subscripts and
jdaggett@8368 3974 superscripts, it is recommended that authors use conditional rules <a
jdaggett@8368 3975 href="#CSS3-CONDITIONAL"
jdaggett@3460 3976 rel=biblioentry>[CSS3-CONDITIONAL]<!--{{CSS3-CONDITIONAL}}--></a> so that
jdaggett@5890 3977 older user agents will still render subscripts and superscripts via the
jdaggett@5890 3978 older mechanism.
jdaggett@5890 3979
jdaggett@5890 3980 <p>Authors should note that fonts typically only provide subscript and
jdaggett@5890 3981 superscript glyphs for a subset of all characters supported by the font.
jdaggett@8280 3982 For example, while subscript and superscript glyphs are often available
jdaggett@8280 3983 for Latin numbers, glyphs for punctuation and letter characters are less
jdaggett@8280 3984 frequently provided. The synthetic fallback rules defined for this
jdaggett@8280 3985 property assure that subscripts and superscripts will always appear but
jdaggett@8280 3986 the appearance may not match author expectations if the font used does not
jdaggett@8280 3987 provide the appropriate alternate glyph for all characters contained in a
jdaggett@8280 3988 subscript or superscript.
jdaggett@8280 3989
jdaggett@8280 3990 <p>This property is not cumulative. Applying it to elements within a
jdaggett@5890 3991 subscript or superscript won't nest the placement of a subscript or
jdaggett@5890 3992 superscript glyph. Images contained within text runs where the value of
jdaggett@8279 3993 this property is ‘<a href="#sub"><code class=property>sub</code></a>’
jdaggett@8279 3994 or ‘<a href="#super"><code class=property>super</code></a>’ will be
jdaggett@8368 3995 drawn just as they would if the value was <a
jdaggett@8368 3996 href="#font-variant-position-normal-value"
jdaggett@8368 3997 title="normal!!font-variant-position">‘<code
jdaggett@8368 3998 class=property>normal</code>’</a>.</p>
jdaggett@8364 3999 <!-- due to lack of consensus, couldn't resolve on exact positioning of text decorations:
jdaggett@8364 4000 http://www.w3.org/2013/06/06-css-minutes.html#item03 -->
jdaggett@8280 4001
jdaggett@8280 4002 <p>Because of these limitations, ‘<a
jdaggett@8280 4003 href="#propdef-font-variant-position"><code
jdaggett@8280 4004 class=property>font-variant-position</code></a>’ is not recommended for
jdaggett@8280 4005 use in user agent stylesheets. Authors should use it in cases where
jdaggett@5890 4006 subscripts or superscripts will only contain the narrow range of
jdaggett@5890 4007 characters supported by the fonts specified.
jdaggett@2509 4008
jdaggett@8368 4009 <p class=note>The variant glyphs use the same baseline as the default
jdaggett@8368 4010 glyphs would use. There is no shift in the placement along the baseline,
jdaggett@8368 4011 so the use of variant glyphs doesn't affect the height of the inline box
jdaggett@8368 4012 or alter the height of the linebox. This makes superscript and subscript
jdaggett@8368 4013 variants ideal for situations where it's important that leading remain
jdaggett@8368 4014 constant, such as in multi-column layout.
jdaggett@8368 4015
jdaggett@2461 4016 <div class=example>
jdaggett@8279 4017 <p>A typical user agent default style for the <a class=tag
jdaggett@8279 4018 href="#sub">sub</a> element:</p>
jdaggett@2461 4019
jdaggett@2461 4020 <pre>sub {
jdaggett@2461 4021 vertical-align: sub;
jdaggett@2461 4022 font-size: smaller;
jdaggett@2461 4023 line-height: normal;
jdaggett@2461 4024 }
jdaggett@2461 4025 </pre>
jdaggett@2461 4026
jdaggett@3460 4027 <p>Using font-variant-position to specify typographic subscripts in a way
jdaggett@3460 4028 that will still show subscripts in older user agents:</p>
jdaggett@3460 4029
jdaggett@3460 4030 <pre>@supports ( font-variant-position: sub ) {
jdaggett@3460 4031
jdaggett@3460 4032 sub {
jdaggett@8280 4033 vertical-align: baseline;
jdaggett@3460 4034 font-size: 100%;
jdaggett@3460 4035 line-height: inherit;
jdaggett@3460 4036 font-variant-position: sub;
jdaggett@3460 4037 }
jdaggett@3460 4038
jdaggett@2461 4039 }
jdaggett@2461 4040 </pre>
jdaggett@2461 4041
jdaggett@4624 4042 <p>User agents that support the ‘<a
jdaggett@4624 4043 href="#propdef-font-variant-position"><code
jdaggett@4624 4044 class=property>font-variant-position</code></a>’ property will select a
jdaggett@4624 4045 subscript variant glyph and render this without adjusting the baseline or
jdaggett@4624 4046 font-size. Older user agents will ignore the ‘<a
jdaggett@4624 4047 href="#propdef-font-variant-position"><code
jdaggett@4624 4048 class=property>font-variant-position</code></a>’ property definition
jdaggett@4624 4049 and use the standard defaults for subscripts.</p>
jdaggett@2461 4050 </div>
jdaggett@2118 4051 <!-- prop: font-variant-caps -->
jdaggett@2118 4052
jdaggett@2118 4053 <h3 id=font-variant-caps-prop><span class=secno>6.6 </span>Capitalization:
jdaggett@1662 4054 the <a href="#propdef-font-variant-caps">font-variant-caps</a> property</h3>
jdaggett@1662 4055
jdaggett@5809 4056 <table class=propdef id=namefont-variant-capsvaluenormal-small-c>
jdaggett@1662 4057 <tbody>
jdaggett@1662 4058 <tr>
jdaggett@1662 4059 <td>Name:
jdaggett@1662 4060
jdaggett@1662 4061 <td><dfn id=propdef-font-variant-caps>font-variant-caps</dfn>
jdaggett@1662 4062
jdaggett@1662 4063 <tr>
jdaggett@1662 4064 <td>Value:
jdaggett@1662 4065
jdaggett@8278 4066 <td><a href="#font-variant-caps-normal-value"
jdaggett@8278 4067 title="normal!!font-variant-caps">normal</a> | <a
jdaggett@8278 4068 href="#small-caps">small-caps</a> | <a
jdaggett@8278 4069 href="#all-small-caps">all-small-caps</a> | <a
jdaggett@8278 4070 href="#petite-caps">petite-caps</a> | <a
jdaggett@8278 4071 href="#all-petite-caps">all-petite-caps</a> | <a
jdaggett@8278 4072 href="#unicase">unicase</a> | <a href="#titling-caps">titling-caps</a>
jdaggett@1662 4073
jdaggett@1662 4074 <tr>
jdaggett@1662 4075 <td>Initial:
jdaggett@1662 4076
jdaggett@1662 4077 <td>normal
jdaggett@1662 4078
jdaggett@1662 4079 <tr>
jdaggett@1662 4080 <td>Applies to:
jdaggett@1662 4081
jdaggett@1662 4082 <td>all elements
jdaggett@1662 4083
jdaggett@1662 4084 <tr>
jdaggett@1662 4085 <td>Inherited:
jdaggett@1662 4086
jdaggett@1662 4087 <td>yes
jdaggett@1662 4088
jdaggett@1662 4089 <tr>
jdaggett@1662 4090 <td>Percentages:
jdaggett@1662 4091
jdaggett@1662 4092 <td>N/A
jdaggett@1662 4093
jdaggett@1662 4094 <tr>
jdaggett@1662 4095 <td>Media:
jdaggett@1662 4096
jdaggett@1662 4097 <td>visual
jdaggett@1662 4098
jdaggett@1662 4099 <tr>
jdaggett@1662 4100 <td>Computed value:
jdaggett@1662 4101
jdaggett@1662 4102 <td>as specified
jdaggett@7377 4103
jdaggett@7377 4104 <tr>
jdaggett@7377 4105 <td>Animatable:
jdaggett@7377 4106
jdaggett@7377 4107 <td>no
jdaggett@1662 4108 </table>
jdaggett@1662 4109
jdaggett@8280 4110 <p>This property allows the selection of alternate glyphs used for small or
jdaggett@8280 4111 petite capitals or for titling. These glyphs are specifically designed to
jdaggett@8280 4112 blend well with the surrounding normal glyphs, to maintain the weight and
jdaggett@8280 4113 readability which suffers when text is simply resized to fit this purpose.
jdaggett@1662 4114
jdaggett@1732 4115 <p>Individual values have the following meanings:
jdaggett@1662 4116
jdaggett@1662 4117 <dl>
jdaggett@8278 4118 <dt><dfn id=font-variant-caps-normal-value
jdaggett@8278 4119 title="normal!!font-variant-caps">normal</dfn>
jdaggett@5809 4120
jdaggett@5809 4121 <dd>None of the features listed below are enabled.
jdaggett@5809 4122
jdaggett@1662 4123 <dt><dfn id=small-caps>small-caps</dfn>
jdaggett@1662 4124
jdaggett@6436 4125 <dd>Enables display of small capitals (OpenType feature: <span
jdaggett@6436 4126 class=tag>smcp</span>). Small-caps glyphs typically use the form of
jdaggett@6436 4127 uppercase letters but are reduced to the size of lowercase letters.
jdaggett@1662 4128 </dl>
jdaggett@1662 4129
jdaggett@1662 4130 <div class=featex><img alt="small-caps example" src=smcp.png></div>
jdaggett@1662 4131
jdaggett@1662 4132 <dl>
jdaggett@1732 4133 <dt><dfn id=all-small-caps>all-small-caps</dfn>
jdaggett@1732 4134
jdaggett@1732 4135 <dd>Enables display of small capitals for both upper and lowercase letters
jdaggett@6436 4136 (OpenType features: <span class=tag>c2sc, smcp</span>).
jdaggett@1732 4137
jdaggett@1662 4138 <dt><dfn id=petite-caps>petite-caps</dfn>
jdaggett@1662 4139
jdaggett@6436 4140 <dd>Enables display of petite capitals (OpenType feature: <span
jdaggett@6436 4141 class=tag>pcap</span>).
jdaggett@1662 4142
jdaggett@1732 4143 <dt><dfn id=all-petite-caps>all-petite-caps</dfn>
jdaggett@1732 4144
jdaggett@1732 4145 <dd>Enables display of petite capitals for both upper and lowercase
jdaggett@6436 4146 letters (OpenType features: <span class=tag>c2pc, pcap</span>).
jdaggett@1732 4147
jdaggett@6648 4148 <dt><dfn id=unicase>unicase</dfn>
jdaggett@6648 4149
jdaggett@6648 4150 <dd>Enables display of mixture of small capitals for uppercase letters
jdaggett@6648 4151 with normal lowercase letters (OpenType feature: <span
jdaggett@6648 4152 class=tag>unic</span>).
jdaggett@6648 4153
jdaggett@1662 4154 <dt><dfn id=titling-caps>titling-caps</dfn>
jdaggett@1662 4155
jdaggett@6436 4156 <dd>Enables display of titling capitals (OpenType feature: <span
jdaggett@6436 4157 class=tag>titl</span>). Uppercase letter glyphs are often designed for
jdaggett@6436 4158 use with lowercase letters. When used in all uppercase titling sequences
jdaggett@6436 4159 they can appear too strong. Titling capitals are designed specifically
jdaggett@6436 4160 for this situation.
jdaggett@1662 4161 </dl>
jdaggett@1662 4162
jdaggett@6648 4163 <p>The availability of these glyphs is based on whether a given feature is
jdaggett@6648 4164 defined or not in the feature list of the font. User agents can optionally
jdaggett@6648 4165 decide this on a per-script basis but should explicitly not decide this on
jdaggett@6648 4166 a per-character basis.
jdaggett@6648 4167
jdaggett@6648 4168 <p>Some fonts may only support a subset or none of the features described
jdaggett@6648 4169 for this property. For backwards compatibility with CSS 2.1, if ‘<a
jdaggett@4624 4170 href="#small-caps"><code class=property>small-caps</code></a>’ or ‘<a
jdaggett@4624 4171 href="#all-small-caps"><code class=property>all-small-caps</code></a>’
jdaggett@4624 4172 is specified but small-caps glyphs are not available for a given font,
jdaggett@4624 4173 user agents should simulate a small-caps font, for example by taking a
jdaggett@6648 4174 normal font and replacing the glyphs for lowercase letters with scaled
jdaggett@6648 4175 versions of the glyphs for uppercase characters (replacing the glyphs for
jdaggett@6648 4176 both upper and lowercase letters in the case of ‘<a
jdaggett@4624 4177 href="#all-small-caps"><code class=property>all-small-caps</code></a>’).
jdaggett@6648 4178
jdaggett@6648 4179 <div class=figure style="padding: 0; margin: auto;"><img alt="synthetic vs.
jdaggett@6648 4180 real small-caps" class=hires src=synthetic-vs-real-small-caps.png
bert@8683 4181 width=512>
jdaggett@6648 4182 <p class=caption>Synthetic vs. real small-caps
jdaggett@6648 4183 </div>
jdaggett@6648 4184
jdaggett@6648 4185 <p>To match the surrounding text, a font may provide alternate glyphs for
jdaggett@6648 4186 caseless characters when these features are enabled but when a user agent
jdaggett@6648 4187 simulates small capitals, it must not attempt to simulate alternates for
jdaggett@6648 4188 codepoints which are considered caseless.
jdaggett@6648 4189
jdaggett@6648 4190 <div class=figure style="padding: 0; margin: auto;"><img alt="caseless
jdaggett@6648 4191 characters with small-caps, all-small-caps enabled" class=hires
bert@8683 4192 src=small-capitals-variations.png width=418>
jdaggett@6648 4193 <p class=caption>Caseless characters with small-caps, all-small-caps
jdaggett@6648 4194 enabled
jdaggett@6648 4195 </div>
jdaggett@6648 4196
jdaggett@6648 4197 <p>If either ‘<a href="#petite-caps"><code
jdaggett@4624 4198 class=property>petite-caps</code></a>’ or ‘<a
jdaggett@4624 4199 href="#all-petite-caps"><code class=property>all-petite-caps</code></a>’
jdaggett@4624 4200 is specified for a font that doesn't support these features, the property
jdaggett@4624 4201 behaves as if ‘<a href="#small-caps"><code
jdaggett@4624 4202 class=property>small-caps</code></a>’ or ‘<a
jdaggett@4624 4203 href="#all-small-caps"><code class=property>all-small-caps</code></a>’,
jdaggett@6648 4204 respectively, had been specified. If ‘<a href="#unicase"><code
jdaggett@6648 4205 class=property>unicase</code></a>’ is specified for a font that doesn't
jdaggett@6648 4206 support that feature, the property behaves as if ‘<a
jdaggett@6648 4207 href="#small-caps"><code class=property>small-caps</code></a>’ was
jdaggett@6648 4208 applied only to lowercased uppercase letters. If ‘<a
jdaggett@6648 4209 href="#titling-caps"><code class=property>titling-caps</code></a>’ is
jdaggett@6648 4210 specified with a font that does not support this feature, this property
jdaggett@6648 4211 has no visible effect. When simulated small capital glyphs are used, for
jdaggett@4624 4212 scripts that lack uppercase and lowercase letters, ‘<a
jdaggett@4624 4213 href="#small-caps"><code class=property>small-caps</code></a>’, ‘<a
jdaggett@4624 4214 href="#all-small-caps"><code class=property>all-small-caps</code></a>’,
jdaggett@4624 4215 ‘<a href="#petite-caps"><code class=property>petite-caps</code></a>’,
jdaggett@4624 4216 ‘<a href="#all-petite-caps"><code
jdaggett@4624 4217 class=property>all-petite-caps</code></a>’ and ‘<a
jdaggett@4624 4218 href="#unicase"><code class=property>unicase</code></a>’ have no visible
jdaggett@2462 4219 effect.
jdaggett@1662 4220
jdaggett@6648 4221 <p>When casing transforms are used to simulate small capitals, the casing
jdaggett@8280 4222 transformations must match those used for the <span
jdaggett@6648 4223 class=property>‘<code class=property>text-transform</code>’</span>
jdaggett@6648 4224 property.
jdaggett@6648 4225
jdaggett@6648 4226 <p>As a last resort, unscaled uppercase letter glyphs in a normal font may
jdaggett@6648 4227 replace glyphs in a small-caps font so that the text appears in all
jdaggett@6648 4228 uppercase letters.
jdaggett@6648 4229
jdaggett@6648 4230 <div class=figure style="padding: 0; margin: auto;"><img alt="using
jdaggett@6648 4231 all-small-caps in acronym-laden text" class=hires
bert@8683 4232 src=acronym-laden-text.png width=596>
jdaggett@6648 4233 <p class=caption>Using small capitals to improve readability in
jdaggett@6648 4234 acronym-laden text
jdaggett@6648 4235 </div>
jdaggett@6648 4236
jdaggett@1662 4237 <div class=example>
jdaggett@1662 4238 <p>Quotes rendered italicised, with small-caps on the first line:</p>
jdaggett@1662 4239
jdaggett@1662 4240 <pre>blockquote { font-style: italic; }
jdaggett@1662 4241 blockquote:first-line { font-variant: small-caps; }
jdaggett@1662 4242
jdaggett@8397 4243 &lt;blockquote><a href="http://lists.w3.org/Archives/Public/www-style/2009Dec/0036.html" style="text-decoration: none; border: none;">I'll be honor-bound to slap them like a haddock.</a>&lt;/blockquote>
jdaggett@1662 4244 </pre>
jdaggett@1662 4245 </div>
jdaggett@2118 4246 <!-- prop: font-variant-numeric -->
jdaggett@2118 4247
jdaggett@2118 4248 <h3 id=font-variant-numeric-prop><span class=secno>6.7 </span>Numerical
jdaggett@1662 4249 formatting: the <a
jdaggett@1662 4250 href="#propdef-font-variant-numeric">font-variant-numeric</a> property</h3>
jdaggett@1662 4251
jdaggett@5809 4252 <table class=propdef id=namefont-variant-numericvaluenormal-ltnu>
jdaggett@1662 4253 <tbody>
jdaggett@1662 4254 <tr>
jdaggett@1662 4255 <td>Name:
jdaggett@1662 4256
jdaggett@1662 4257 <td><dfn id=propdef-font-variant-numeric>font-variant-numeric</dfn>
jdaggett@1662 4258
jdaggett@1662 4259 <tr>
jdaggett@1662 4260 <td>Value:
jdaggett@1662 4261
jdaggett@8278 4262 <td><a href="#font-variant-numeric-normal-value"
jdaggett@8278 4263 title="normal!!font-variant-numeric">normal</a> | [ <a
jdaggett@8225 4264 href="#numeric-figure-values"><var>&lt;numeric-figure-values&gt;</var></a>
jdaggett@8225 4265 || <a
jdaggett@8225 4266 href="#numeric-spacing-values"><var>&lt;numeric-spacing-values&gt;</var></a>
jdaggett@8225 4267 || <a
jdaggett@8225 4268 href="#numeric-fraction-values"><var>&lt;numeric-fraction-values&gt;</var></a>
jdaggett@8225 4269 || <a href="#ordinal">ordinal</a> || <a
jdaggett@8225 4270 href="#slashed-zero">slashed-zero</a> ]
jdaggett@1662 4271
jdaggett@1662 4272 <tr>
jdaggett@1662 4273 <td>Initial:
jdaggett@1662 4274
jdaggett@1662 4275 <td>normal
jdaggett@1662 4276
jdaggett@1662 4277 <tr>
jdaggett@1662 4278 <td>Applies to:
jdaggett@1662 4279
jdaggett@1662 4280 <td>all elements
jdaggett@1662 4281
jdaggett@1662 4282 <tr>
jdaggett@1662 4283 <td>Inherited:
jdaggett@1662 4284
jdaggett@1662 4285 <td>yes
jdaggett@1662 4286
jdaggett@1662 4287 <tr>
jdaggett@1662 4288 <td>Percentages:
jdaggett@1662 4289
jdaggett@1662 4290 <td>N/A
jdaggett@1662 4291
jdaggett@1662 4292 <tr>
jdaggett@1662 4293 <td>Media:
jdaggett@1662 4294
jdaggett@1662 4295 <td>visual
jdaggett@1662 4296
jdaggett@1662 4297 <tr>
jdaggett@1662 4298 <td>Computed value:
jdaggett@1662 4299
jdaggett@1662 4300 <td>as specified
jdaggett@7377 4301
jdaggett@7377 4302 <tr>
jdaggett@7377 4303 <td>Animatable:
jdaggett@7377 4304
jdaggett@7377 4305 <td>no
jdaggett@1662 4306 </table>
jdaggett@1662 4307
jdaggett@8311 4308 <p>Specifies control over numerical forms. The example below shows how some
jdaggett@8311 4309 of these values can be combined to influence the rendering of tabular data
jdaggett@8311 4310 with fonts that support these features. Within normal paragraph text,
jdaggett@8311 4311 proportional numbers are used while tabular numbers are used so that
jdaggett@8311 4312 columns of numbers line up properly:
jdaggett@1662 4313
jdaggett@1662 4314 <div class=figure style="padding: 0; margin: auto;"><img alt="combining
jdaggett@1662 4315 number styles" src=numberstyles.png>
jdaggett@1662 4316 <p class=caption>Using number styles
jdaggett@1662 4317 </div>
jdaggett@1662 4318
jdaggett@8311 4319 <p>Possible combinations:
jdaggett@8311 4320
jdaggett@8311 4321 <pre
jdaggett@8311 4322 class=prod><dfn id=numeric-figure-values><var>&lt;numeric-figure-values&gt;</var></dfn> = [ <a href="#lining-nums">lining-nums</a> | <a href="#oldstyle-nums">oldstyle-nums</a> ]</pre>
jdaggett@8311 4323
jdaggett@8311 4324 <pre
jdaggett@8311 4325 class=prod><dfn id=numeric-spacing-values><var>&lt;numeric-spacing-values&gt;</var></dfn> = [ <a href="#proportional-nums">proportional-nums</a> | <a href="#tabular-nums">tabular-nums</a> ]</pre>
jdaggett@8311 4326
jdaggett@8311 4327 <pre
jdaggett@8311 4328 class=prod><dfn id=numeric-fraction-values><var>&lt;numeric-fraction-values&gt;</var></dfn> = [ <a href="#diagonal-fractions">diagonal-fractions</a> | <a href="#stacked-fractions">stacked-fractions</a> ]</pre>
jdaggett@8311 4329
jdaggett@8311 4330 <p>Individual values have the following meanings:
jdaggett@8311 4331
jdaggett@1662 4332 <dl>
jdaggett@8311 4333 <dt><dfn id=font-variant-numeric-normal-value
jdaggett@8311 4334 title="normal!!font-variant-numeric">normal</dfn>
jdaggett@8311 4335
jdaggett@8311 4336 <dd>None of the features listed below are enabled.
jdaggett@8311 4337
jdaggett@8311 4338 <dt><dfn id=lining-nums>lining-nums</dfn>
jdaggett@8311 4339
jdaggett@8311 4340 <dd>Enables display of lining numerals (OpenType feature: <span
jdaggett@8311 4341 class=tag>lnum</span>).
jdaggett@8311 4342
jdaggett@8311 4343 <dt><dfn id=oldstyle-nums>oldstyle-nums</dfn>
jdaggett@8311 4344
jdaggett@8311 4345 <dd>Enables display of old-style numerals (OpenType feature: <span
jdaggett@8311 4346 class=tag>onum</span>).
jdaggett@8311 4347
jdaggett@8311 4348 <dt><dfn id=proportional-nums>proportional-nums</dfn>
jdaggett@8311 4349
jdaggett@8311 4350 <dd>Enables display of proportional numerals (OpenType feature: <span
jdaggett@8311 4351 class=tag>pnum</span>).
jdaggett@8311 4352
jdaggett@8311 4353 <dt><dfn id=tabular-nums>tabular-nums</dfn>
jdaggett@8311 4354
jdaggett@8311 4355 <dd>Enables display of tabular numerals (OpenType feature: <span
jdaggett@8311 4356 class=tag>tnum</span>).
jdaggett@8311 4357
jdaggett@1662 4358 <dt><dfn id=diagonal-fractions>diagonal-fractions</dfn>
jdaggett@1662 4359
jdaggett@6436 4360 <dd>Enables display of lining diagonal fractions (OpenType feature: <span
jdaggett@6436 4361 class=tag>frac</span>).
jdaggett@1662 4362 </dl>
jdaggett@1662 4363
jdaggett@1662 4364 <div class=featex><img alt="diagonal fraction example" src=frac.png></div>
jdaggett@1662 4365
jdaggett@1662 4366 <dl>
jdaggett@1662 4367 <dt><dfn id=stacked-fractions>stacked-fractions</dfn>
jdaggett@1662 4368
jdaggett@6436 4369 <dd>Enables display of lining stacked fractions (OpenType feature: <span
jdaggett@6436 4370 class=tag>afrc</span>).
jdaggett@1662 4371 </dl>
jdaggett@1662 4372
jdaggett@1662 4373 <div class=featex><img alt="stacked fraction example" src=afrc.png></div>
jdaggett@1662 4374
jdaggett@1662 4375 <dl>
jdaggett@3638 4376 <dt><dfn id=ordinal>ordinal</dfn>
jdaggett@3638 4377
jdaggett@3638 4378 <dd>Enables display of forms used with ordinal numbers (OpenType feature:
jdaggett@6436 4379 <span class=tag>ordn</span>).
jdaggett@3638 4380
jdaggett@1662 4381 <dt><dfn id=slashed-zero>slashed-zero</dfn>
jdaggett@1662 4382
jdaggett@6436 4383 <dd>Enables display of slashed zeros (OpenType feature: <span
jdaggett@6436 4384 class=tag>zero</span>).
jdaggett@1662 4385 </dl>
jdaggett@1662 4386
jdaggett@1662 4387 <div class=featex><img alt="slashed zero example" src=zero.png></div>
jdaggett@1662 4388
jdaggett@1662 4389 <div class=example id=steak-marinade>
jdaggett@1662 4390 <p>A simple flank steak marinade recipe, rendered with automatic fractions
jdaggett@1662 4391 and old-style numerals:</p>
jdaggett@1662 4392
jdaggett@1662 4393 <pre>.amount { font-variant-numeric: oldstyle-nums diagonal-fractions; }
jdaggett@1662 4394
jdaggett@1662 4395 &lt;h4>Steak marinade:&lt;/h4>
jdaggett@1662 4396 &lt;ul>
jdaggett@1662 4397 &lt;li>&lt;span class="amount">2&lt;/span> tbsp olive oil&lt;/li>
jdaggett@1662 4398 &lt;li>&lt;span class="amount">1&lt;/span> tbsp lemon juice&lt;/li>
jdaggett@1662 4399 &lt;li>&lt;span class="amount">1&lt;/span> tbsp soy sauce&lt;/li>
jdaggett@1662 4400 &lt;li>&lt;span class="amount">1 1/2&lt;/span> tbsp dry minced onion&lt;/li>
jdaggett@1662 4401 &lt;li>&lt;span class="amount">2 1/2&lt;/span> tsp italian seasoning&lt;/li>
jdaggett@1732 4402 &lt;li>Salt &amp;amp; pepper&lt;/li>
jdaggett@1662 4403 &lt;/ul>
jdaggett@1662 4404
jdaggett@5596 4405 &lt;p>Mix the meat with the marinade and let it sit covered in the refrigerator
jdaggett@5596 4406 for a few hours or overnight.&lt;/p>
jdaggett@1662 4407 </pre>
jdaggett@8311 4408
jdaggett@8311 4409 <p>Note that the fraction feature is only applied to values not the entire
jdaggett@8311 4410 paragraph. Fonts often implement this feature using contextual rules
jdaggett@8311 4411 based on the use of the slash (‘<code class=css>/</code>’) character.
jdaggett@8311 4412 As such, it's not suitable for use as a paragraph-level style.</p>
jdaggett@1662 4413 </div>
jdaggett@2118 4414 <!-- prop: font-variant-alternates -->
jdaggett@2118 4415
jdaggett@2118 4416 <h3 id=font-variant-alternates-prop><span class=secno>6.8 </span>Alternates
jdaggett@2118 4417 and swashes: the <a
jdaggett@2118 4418 href="#propdef-font-variant-alternates">font-variant-alternates</a>
jdaggett@2118 4419 property</h3>
jdaggett@2118 4420
jdaggett@6176 4421 <table class=propdef id=namefont-variant-alternatesvaluenormal-s>
jdaggett@2118 4422 <tbody>
jdaggett@2118 4423 <tr>
jdaggett@2118 4424 <td>Name:
jdaggett@2118 4425
jdaggett@2118 4426 <td><dfn
jdaggett@2118 4427 id=propdef-font-variant-alternates>font-variant-alternates</dfn>
jdaggett@2118 4428
jdaggett@2118 4429 <tr>
jdaggett@2118 4430 <td>Value:
jdaggett@2118 4431
jdaggett@8225 4432 <td>normal | [ <a href="#stylistic"
jdaggett@8225 4433 title=stylistic>stylistic(&lt;feature-value-name&gt;)</a> || <a
jdaggett@8225 4434 href="#historical-forms">historical-forms</a> || <a href="#styleset"
jdaggett@8225 4435 title=styleset>styleset(&lt;feature-value-name&gt; #)</a> || <a
jdaggett@8225 4436 href="#character-variant"
jdaggett@8225 4437 title=character-variant>character-variant(&lt;feature-value-name&gt;
jdaggett@8225 4438 #)</a> || <a href="#swash"
jdaggett@8225 4439 title=swash>swash(&lt;feature-value-name&gt;)</a> || <a
jdaggett@8225 4440 href="#ornaments"
jdaggett@8225 4441 title=ornaments>ornaments(&lt;feature-value-name&gt;)</a> || <a
jdaggett@8225 4442 href="#annotation"
jdaggett@8225 4443 title=annotation>annotation(&lt;feature-value-name&gt;)</a> ]
jdaggett@2118 4444
jdaggett@2118 4445 <tr>
jdaggett@2118 4446 <td>Initial:
jdaggett@2118 4447
jdaggett@2118 4448 <td>normal
jdaggett@2118 4449
jdaggett@2118 4450 <tr>
jdaggett@2118 4451 <td>Applies to:
jdaggett@2118 4452
jdaggett@2118 4453 <td>all elements
jdaggett@2118 4454
jdaggett@2118 4455 <tr>
jdaggett@2118 4456 <td>Inherited:
jdaggett@2118 4457
jdaggett@2118 4458 <td>yes
jdaggett@2118 4459
jdaggett@2118 4460 <tr>
jdaggett@2118 4461 <td>Percentages:
jdaggett@2118 4462
jdaggett@2118 4463 <td>N/A
jdaggett@2118 4464
jdaggett@2118 4465 <tr>
jdaggett@2118 4466 <td>Media:
jdaggett@2118 4467
jdaggett@2118 4468 <td>visual
jdaggett@2118 4469
jdaggett@2118 4470 <tr>
jdaggett@2118 4471 <td>Computed value:
jdaggett@2118 4472
jdaggett@2118 4473 <td>as specified
jdaggett@7377 4474
jdaggett@7377 4475 <tr>
jdaggett@7377 4476 <td>Animatable:
jdaggett@7377 4477
jdaggett@7377 4478 <td>no
jdaggett@2118 4479 </table>
jdaggett@2118 4480
jdaggett@2118 4481 <p>For any given character, fonts can provide a variety of alternate glyphs
jdaggett@2118 4482 in addition to the default glyph for that character. This property
jdaggett@2118 4483 provides control over the selection of these alternate glyphs.
jdaggett@2118 4484
jdaggett@8311 4485 <p>For many of the property values listed below, several different
jdaggett@8311 4486 alternate glyphs are available. How many alternates are available and what
jdaggett@8356 4487 they represent is font-specific, so these are each marked <dfn
jdaggett@8356 4488 id=font-specific>font specific</dfn> in the value definitions below.
jdaggett@8356 4489 Because the nature of these alternates is font-specific, the <a
jdaggett@8311 4490 href="#at-font-feature-values-rule"><code>@font-feature-values</code></a>
jdaggett@8311 4491 rule is used to define values for a specific font family or set of
jdaggett@8311 4492 families that associate a font-specific numeric
jdaggett@8311 4493 <code>&lt;feature-index&gt;</code> with a custom
jdaggett@8311 4494 <code>&lt;feature-value-name&gt;</code>, which is then used in this
jdaggett@8311 4495 property to select specific alternates:
jdaggett@8311 4496
jdaggett@8311 4497 <pre>@font-feature-values Noble Script { @swash { swishy: 1; flowing: 2; } }
jdaggett@8311 4498
jdaggett@8311 4499 p {
jdaggett@8311 4500 font-family: Noble Script;
jdaggett@8311 4501 font-variant-alternates: swash(flowing); /* use swash alternate #2 */
jdaggett@8311 4502 }</pre>
jdaggett@8311 4503
jdaggett@8312 4504 <p>When a particular <code>&lt;feature-value-name&gt;</code> has not been
jdaggett@8312 4505 defined for a given family or for a particular feature type, the computed
jdaggett@8312 4506 value must be the same as if it had been defined. However, property values
jdaggett@8312 4507 that contain these undefined <code>&lt;feature-value-name&gt;</code>
jdaggett@8312 4508 identifiers must be ignored when choosing glyphs.
jdaggett@8312 4509
jdaggett@8312 4510 <pre>/* these two style rules are effectively the same */
jdaggett@8312 4511 p { font-variant-alternates: swash(unknown-value); } /* not a defined value, ignored */
jdaggett@8312 4512 p { font-variant-alternates: normal; }
jdaggett@8312 4513 </pre>
jdaggett@8312 4514
jdaggett@8312 4515 <p>This allows values to be defined and used for a given set of font
jdaggett@8312 4516 families but ignored if fallback occurs, since the font family name would
jdaggett@8312 4517 be different. If a given value is outside the range supported by a given
jdaggett@8312 4518 font, the value is ignored. These values never apply to generic font
jdaggett@8312 4519 families.
jdaggett@2556 4520
jdaggett@2118 4521 <p>Individual values have the following meanings:
jdaggett@2118 4522
jdaggett@2118 4523 <dl>
jdaggett@8278 4524 <dt><dfn id=font-variant-alternates-normal-value
jdaggett@8278 4525 title="normal!!font-variant-alternates">normal</dfn>
jdaggett@5809 4526
jdaggett@5809 4527 <dd>None of the features listed below are enabled.
jdaggett@5809 4528
jdaggett@2118 4529 <dt><dfn id=historical-forms>historical-forms</dfn>
jdaggett@2118 4530
jdaggett@6436 4531 <dd>Enables display of historical forms (OpenType feature: <span
jdaggett@6436 4532 class=tag>hist</span>).
jdaggett@2118 4533 </dl>
jdaggett@2118 4534
jdaggett@2118 4535 <div class=featex><img alt="historical form example" src=hist.png></div>
jdaggett@2118 4536
jdaggett@2118 4537 <dl>
jdaggett@8311 4538 <dt><dfn id=stylistic
jdaggett@8311 4539 title=stylistic>stylistic(&lt;feature-value-name&gt;)</dfn>
jdaggett@8311 4540
jdaggett@8356 4541 <dd>Enables display of stylistic alternates (<a
jdaggett@8356 4542 href="#font-specific"><em>font specific</em></a>, OpenType feature: <span
jdaggett@8356 4543 class=tag>salt &lt;feature-index&gt;</span>).
jdaggett@8311 4544 </dl>
jdaggett@8311 4545
jdaggett@8311 4546 <div class=featex><img alt="stylistic alternate example" src=salt.png></div>
jdaggett@8311 4547
jdaggett@8311 4548 <dl>
jdaggett@8225 4549 <dt><dfn id=styleset title=styleset>styleset(&lt;feature-value-name&gt;
jdaggett@8225 4550 #)</dfn>
jdaggett@2118 4551
jdaggett@8356 4552 <dd>Enables display with stylistic sets (<a href="#font-specific"><em>font
jdaggett@8356 4553 specific</em></a>, OpenType feature: <span
jdaggett@8356 4554 class=tag>ss&lt;feature-index&gt;</span> OpenType currently defines <span
jdaggett@8356 4555 class=tag>ss01</span> through <span class=tag>ss20</span>).
jdaggett@2118 4556 </dl>
jdaggett@2118 4557
jdaggett@2118 4558 <div class=featex><img alt="styleset example" src=ssnn.png></div>
jdaggett@2118 4559
jdaggett@2118 4560 <dl>
jdaggett@8225 4561 <dt><dfn id=character-variant
jdaggett@8225 4562 title=character-variant>character-variant(&lt;feature-value-name&gt;
jdaggett@8225 4563 #)</dfn>
jdaggett@2118 4564
jdaggett@8356 4565 <dd>Enables display of specific character variants (<a
jdaggett@8356 4566 href="#font-specific"><em>font specific</em></a>, OpenType feature: <span
jdaggett@6436 4567 class=tag>cv&lt;feature-index&gt;</span> OpenType currently defines <span
jdaggett@6436 4568 class=tag>cv01</span> through <span class=tag>cv99</span>).
jdaggett@2118 4569
jdaggett@8225 4570 <dt><dfn id=swash title=swash>swash(&lt;feature-value-name&gt;)</dfn>
jdaggett@2118 4571
jdaggett@8356 4572 <dd>Enables display of swash glyphs (<a href="#font-specific"><em>font
jdaggett@8356 4573 specific</em></a>, OpenType feature: <span class=tag>swsh
jdaggett@8356 4574 &lt;feature-index&gt;, cswh &lt;feature-index&gt;</span>).
jdaggett@2118 4575 </dl>
jdaggett@2118 4576
jdaggett@2118 4577 <div class=featex><img alt="swash example" src=swsh.png></div>
jdaggett@2118 4578
jdaggett@2118 4579 <dl>
jdaggett@8225 4580 <dt><dfn id=ornaments
jdaggett@7060 4581 title=ornaments>ornaments(&lt;feature-value-name&gt;)</dfn>
jdaggett@2118 4582
jdaggett@2118 4583 <dd>Enables replacement of default glyphs with ornaments, if provided in
jdaggett@8356 4584 the font (<a href="#font-specific"><em>font specific</em></a>, OpenType
jdaggett@8356 4585 feature: <span class=tag>ornm &lt;feature-index&gt;</span>). Some fonts
jdaggett@8356 4586 may offer ornament glyphs as alternates for a wide collection of
jdaggett@8356 4587 characters; however, displaying arbitrary characters (e.g.,
jdaggett@8356 4588 alphanumerics) as ornaments is poor practice as it distorts the semantics
jdaggett@8356 4589 of the data. Font designers are encouraged to encode all ornaments
jdaggett@8356 4590 (except those explicitly encoded in the Unicode Dingbats blocks, etc.) as
jdaggett@8356 4591 alternates for the bullet character (U+2022) to allow authors to select
jdaggett@8356 4592 the desired glyph using ‘<a href="#ornaments"><code
jdaggett@8356 4593 class=property>ornaments</code></a>’.
jdaggett@2118 4594 </dl>
jdaggett@2118 4595
jdaggett@2118 4596 <div class=featex><img alt="ornaments example" src=ornm.png></div>
jdaggett@2118 4597
jdaggett@2118 4598 <dl>
jdaggett@8225 4599 <dt><dfn id=annotation
jdaggett@7060 4600 title=annotation>annotation(&lt;feature-value-name&gt;)</dfn>
jdaggett@2118 4601
jdaggett@8356 4602 <dd>Enables display of alternate annotation forms (<a
jdaggett@8356 4603 href="#font-specific"><em>font specific</em></a>, OpenType feature: <span
jdaggett@8356 4604 class=tag>nalt &lt;feature-index&gt;</span>).
jdaggett@2118 4605 </dl>
jdaggett@2118 4606
jdaggett@2118 4607 <div class=featex><img alt="alternate annotation form example"
jdaggett@2118 4608 src=nalt.png></div>
jdaggett@2118 4609
jdaggett@2472 4610 <h3 id=font-feature-values><span class=secno>6.9 </span>Defining font
jdaggett@8311 4611 specific alternates: the <dfn id=at-font-feature-values-rule
jdaggett@8311 4612 style="font-weight: inherit; font-style:
jdaggett@8311 4613 inherit"><code>@font-feature-values</code></dfn> rule</h3>
jdaggett@2472 4614
jdaggett@4624 4615 <p>Several of the possible values of ‘<a
jdaggett@4624 4616 href="#propdef-font-variant-alternates"><code
jdaggett@4624 4617 class=property>font-variant-alternates</code></a>’ listed above are
jdaggett@8356 4618 labeled as <a href="#font-specific"><em>font specific</em></a>. For these
jdaggett@8356 4619 features fonts may define not just a single glyph but a set of alternate
jdaggett@8356 4620 glyphs with an index to select a given alternate. Since these are font
jdaggett@8356 4621 family specific, the <a
jdaggett@8311 4622 href="#at-font-feature-values-rule"><code>@font-feature-values</code></a>
jdaggett@8356 4623 rule is used to define named values for these indices for a given family.
jdaggett@8356 4624
jdaggett@8356 4625 <p class=note>See the <a href="#om-fontfeaturevalues">object model
jdaggett@8356 4626 reference section</a> for a description of the interfaces used to modify
jdaggett@8356 4627 these rules via the CSS Object Model.
jdaggett@8356 4628
jdaggett@8356 4629 <div class=example>
jdaggett@8356 4630 <p>In the case of the swash Q in the example shown above, the swash could
jdaggett@8356 4631 be specified using these style rules:</p>
jdaggett@8356 4632
jdaggett@8356 4633 <pre>
jdaggett@7041 4634
jdaggett@2472 4635 @font-feature-values Jupiter Sans {
jdaggett@7041 4636 @swash {
jdaggett@7041 4637 delicate: 1;
jdaggett@7041 4638 flowing: 2;
jdaggett@7041 4639 }
jdaggett@2472 4640 }
jdaggett@2472 4641
jdaggett@2472 4642 h2 { font-family: Jupiter Sans, sans-serif; }
jdaggett@2472 4643
jdaggett@2472 4644 /* show the second swash variant in h2 headings */
jdaggett@2472 4645 h2:first-letter { font-variant-alternates: swash(flowing); }
jdaggett@2472 4646
jdaggett@2479 4647 &lt;h2>Quick&lt;/h2></pre>
jdaggett@2472 4648
jdaggett@8356 4649 <p>When Jupiter Sans is present, the second alternate swash alternate will
jdaggett@8356 4650 be displayed. When not present, no swash character will be shown, since
jdaggett@8356 4651 the specific named value "flowing" is only defined for the Jupiter Sans
jdaggett@8356 4652 family. The @-mark indicates the name of the property value for which a
jdaggett@8356 4653 named value can be used. The name "flowing" is chosen by the author. The
jdaggett@8356 4654 index that represents each alternate is defined within a given font's
jdaggett@8356 4655 data.</p>
jdaggett@8356 4656 </div>
jdaggett@8356 4657
jdaggett@8356 4658 <h4 id=basic-syntax><span class=secno>6.9.1 </span>Basic syntax</h4>
jdaggett@8356 4659
jdaggett@8356 4660 <p>An <a
jdaggett@8356 4661 href="#at-font-feature-values-rule"><code>@font-feature-values</code></a>
jdaggett@8356 4662 rule is composed of a list of font families followed by a block containing
jdaggett@8356 4663 individual <a href="#featurevalueblock"><i
jdaggett@8356 4664 title="feature_value_block">feature value blocks</i></a> that take the
jdaggett@8356 4665 form of @-rules. Each block defines a set of named values for a specific
jdaggett@8356 4666 font feature when a given set of font families is used. Effectively, they
jdaggett@8356 4667 define a mapping of ⟨family, feature, ident⟩ → ⟨values⟩ where
jdaggett@8356 4668 ⟨values⟩ are the numeric indices used for specific features defined
jdaggett@8356 4669 for a given font.
jdaggett@8031 4670
jdaggett@8031 4671 <p>In terms of the grammar, this specification defines the following
jdaggett@8312 4672 productions:
jdaggett@8225 4673
jdaggett@8225 4674 <pre><dfn id=fontfeaturevaluesrule>font_feature_values_rule</dfn>
jdaggett@8225 4675 : <a href="#fontfeaturevaluessym"><i>FONT_FEATURE_VALUES_SYM</i></a> <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* <a href="#fontfamilynamelist"><i>font_family_name_list</i></a> <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>*
jdaggett@8225 4676 '{' <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* <a href="#featurevalueblock"><i>feature_value_block</i></a>? [ <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* <a href="#featurevalueblock"><i>feature_value_block</i></a>? ]* '}' <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>*
jdaggett@8225 4677 ;
jdaggett@8225 4678
jdaggett@8225 4679 <dfn id=fontfamilynamelist>font_family_name_list</dfn>
jdaggett@8225 4680 : <a href="#fontfamilyname"><i>font_family_name</i></a> [ <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* ',' <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* <a href="#fontfamilyname"><i>font_family_name</i></a> ]*
jdaggett@8225 4681 ;
jdaggett@8225 4682
jdaggett@8225 4683 <dfn id=fontfamilyname>font_family_name</dfn>
jdaggett@8225 4684 : <a href="http://www.w3.org/TR/CSS21/syndata.html#tokenization"><i>STRING</i></a> | [ <a href="http://www.w3.org/TR/CSS21/syndata.html#tokenization"><i>IDENT</i></a> [ <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* <a href="http://www.w3.org/TR/CSS21/syndata.html#tokenization"><i>IDENT</i></a> ]* ]
jdaggett@8225 4685 ;
jdaggett@8225 4686
jdaggett@8225 4687 <dfn id=featurevalueblock>feature_value_block</dfn>
jdaggett@8225 4688 : <a href="#featuretype"><i>feature_type</i></a> <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>*
jdaggett@8225 4689 '{' <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* <a href="#featurevaluedefinition"><i>feature_value_definition</i></a>? [ <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* ';' <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* <a href="#featurevaluedefinition"><i>feature_value_definition</i></a>? ]* '}' <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>*
jdaggett@8225 4690 ;
jdaggett@8225 4691
jdaggett@8225 4692 <dfn id=featuretype>feature_type</dfn>:
jdaggett@8225 4693 <a href="http://www.w3.org/TR/CSS21/syndata.html#tokenization"><i>ATKEYWORD</i></a>
jdaggett@8225 4694 ;
jdaggett@8225 4695
jdaggett@8225 4696 <dfn id=featurevaluedefinition>feature_value_definition</dfn>
jdaggett@8225 4697 : <a href="http://www.w3.org/TR/CSS21/syndata.html#tokenization"><i>IDENT</i></a> <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* ':' <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* <a href="http://www.w3.org/TR/CSS21/syndata.html#tokenization"><i>NUMBER</i></a> [ <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* <a href="http://www.w3.org/TR/CSS21/syndata.html#tokenization"><i>NUMBER</i></a> ]*
jdaggett@8225 4698 ;
jdaggett@8225 4699 </pre>
jdaggett@8225 4700
jdaggett@8032 4701 <p>The following new token is introduced:
jdaggett@8032 4702
jdaggett@8225 4703 <pre>@{F}{O}{N}{T}{-}{F}{E}{A}{T}{U}{R}{E}{-}{V}{A}{L}{U}{E}{S} {return <dfn id=fontfeaturevaluessym>FONT_FEATURE_VALUES_SYM</dfn>;}
jdaggett@2118 4704 </pre>
jdaggett@2118 4705
jdaggett@8356 4706 <p><a href="#featurevalueblock"><i title="feature_value_block">Feature
jdaggett@8356 4707 value blocks</i></a> are handled as <a
jdaggett@8356 4708 href="http://www.w3.org/TR/CSS2/syndata.html#at-rules">at-rules</a>, they
jdaggett@8356 4709 consist of everything up to the next block or semi-colon, whichever comes
jdaggett@8356 4710 first.
jdaggett@8356 4711
jdaggett@8356 4712 <p>The <a href="#fontfamilynamelist"><i title="font_family_name_list">font
jdaggett@8356 4713 family list</i></a> is a comma-delimited list of <a
jdaggett@8356 4714 href="#fontfamilyname"><i title="font_family_name">font family
jdaggett@8356 4715 names</i></a> that match the definition of <a
jdaggett@8356 4716 href="#family-name-value"><var>&lt;family-name&gt;</var></a> for the <a
jdaggett@8278 4717 href="#propdef-font-family" title="font-family!!property">‘<code
jdaggett@8356 4718 class=property>font-family</code>’</a> property. This means that only
jdaggett@8356 4719 named font families are allowed, rules that include generic or system
jdaggett@8356 4720 fonts in the list of font families are syntax errors. However, if a user
jdaggett@8356 4721 agent defines a generic font to be a specific named font (e.g. Helvetica),
jdaggett@8356 4722 the settings associated with that family name will be used. If syntax
jdaggett@8356 4723 errors occur within the font family list, the entire rule must be ignored.
jdaggett@8356 4724
jdaggett@8356 4725 <p>Within <a href="#featurevalueblock"><i
jdaggett@8356 4726 title="feature_value_block">feature value blocks</i></a>, the <a
jdaggett@8356 4727 href="#featuretype"><i title="feature_type">feature type</i></a> is
jdaggett@8356 4728 ‘<code class=css>@</code>’ followed by the name of one of the <a
jdaggett@8356 4729 href="#font-specific"><em>font specific</em></a> property values of ‘<a
jdaggett@8356 4730 href="#propdef-font-variant-alternates"><code
jdaggett@8356 4731 class=property>font-variant-alternates</code></a>’ (e.g. <a
jdaggett@8356 4732 href="#swash"><code>@swash</code></a>). The identifiers used within
jdaggett@8356 4733 feature value definitions follow the rules of CSS user identifiers and are
jdaggett@8356 4734 case-sensitive. They are unique only for a given set of font families and
jdaggett@8356 4735 <a href="#featuretype"><i title="feature_type">feature type</i></a>. The
jdaggett@8356 4736 same identifier used with a different <a href="#featuretype"><i
jdaggett@8356 4737 title="feature_type">feature type</i></a> is treated as a separate and
jdaggett@8356 4738 distinct value. If the same identifier is defined mulitple times for a
jdaggett@8356 4739 given <a href="#featuretype"><i title="feature_type">feature type</i></a>
jdaggett@8356 4740 and font family, the last defined value is used. Values associated with a
jdaggett@8356 4741 given identifier are limited to integer values 0 or greater.
jdaggett@8356 4742
jdaggett@8356 4743 <p>When syntax errors occur within a <a href="#featurevaluedefinition"><i
jdaggett@8356 4744 title="feature_value_definition">feature value definition</i></a>, such as
jdaggett@8356 4745 invalid identifiers or values, the entire <a
jdaggett@8356 4746 href="#featurevaluedefinition"><i title="feature_value_definition">feature
jdaggett@8356 4747 value definition</i></a> must be omitted, just as syntax errors in style
jdaggett@8356 4748 declarations are handled. When the <a href="#featuretype"><i
jdaggett@8356 4749 title="feature_type">feature type</i></a> is invalid, the entire
jdaggett@8356 4750 associated <a href="#featurevalueblock"><i
jdaggett@8356 4751 title="feature_value_block">feature value block</i></a> must be ignored.
jdaggett@8356 4752
jdaggett@8356 4753 <div class=example>
jdaggett@8356 4754 <p>Rules that are equivalent given syntax error handling:</p>
jdaggett@8356 4755
jdaggett@8356 4756 <pre>@font-feature-values Bongo {
jdaggett@7679 4757 @swash { ornate: 1; }
jdaggett@7679 4758 annotation { boxed: 4; } /* should be @annotation! */
jdaggett@8031 4759 @swash { double-loops: 1; flowing: -1; } /* negative value */
jdaggett@8031 4760 @ornaments ; /* incomplete definition */
jdaggett@8031 4761 @styleset { double-W: 14; sharp-terminals: 16 1 } /* missing ; */
jdaggett@8356 4762 <a href="http://www.angryalien.com/0504/shiningbunnies.html" style="text-decoration: none; border: none;">redrum</a> /* random editing mistake */
jdaggett@7679 4763 }</pre>
jdaggett@7679 4764
jdaggett@8356 4765 <p>The example above is equivalent to:</p>
jdaggett@8356 4766
jdaggett@8356 4767 <pre>@font-feature-values Bongo {
jdaggett@7679 4768 @swash { ornate: 1; }
jdaggett@8031 4769 @swash { double-loops: 1; }
jdaggett@8031 4770 @styleset { double-W: 14; sharp-terminals: 16 1; }
jdaggett@7679 4771 }</pre>
jdaggett@8356 4772 </div>
jdaggett@7096 4773
jdaggett@8311 4774 <p>If multiple <a
jdaggett@8311 4775 href="#at-font-feature-values-rule"><code>@font-feature-values</code></a>
jdaggett@8356 4776 rules are defined for a given family, the resulting values definitions are
jdaggett@8356 4777 the union of the definitions contained within these rules. This allows a
jdaggett@8356 4778 set of named values to be defined for a given font family globally for a
jdaggett@8356 4779 site and specific additions made per-page.
jdaggett@8356 4780
jdaggett@8356 4781 <div class=example>
jdaggett@8356 4782 <p>Using both site-wide and per-page feature values:</p>
jdaggett@8356 4783
jdaggett@8356 4784 <pre>
jdaggett@2472 4785 site.css:
jdaggett@2472 4786
jdaggett@2472 4787 @font-feature-values Mercury Serif {
jdaggett@7041 4788 @styleset {
jdaggett@7041 4789 stacked-g: 3; /* "two-storey" versions of g, a */
jdaggett@7041 4790 stacked-a: 4;
jdaggett@7041 4791 }
jdaggett@2472 4792 }
jdaggett@2472 4793
jdaggett@2472 4794 page.css:
jdaggett@8277 4795
jdaggett@2472 4796 @font-feature-values Mercury Serif {
jdaggett@7041 4797 @styleset {
jdaggett@7041 4798 geometric-m: 7; /* alternate version of m */
jdaggett@7041 4799 }
jdaggett@2472 4800 }
jdaggett@8277 4801
jdaggett@2472 4802 body {
jdaggett@2472 4803 font-family: Mercury Serif, serif;
jdaggett@2472 4804
jdaggett@2472 4805 /* enable both the use of stacked g and alternate m */
jdaggett@2472 4806 font-variant-alternates: styleset(stacked-g, geometric-m);
jdaggett@2472 4807 }</pre>
jdaggett@8356 4808 </div>
jdaggett@8356 4809
jdaggett@8356 4810 <div class=example>
jdaggett@8356 4811 <p>Using a commonly named value allows authors to use a single style rule
jdaggett@8356 4812 to cover a set of fonts for which the underlying selector is different
jdaggett@8356 4813 for each font. If either font in the example below is found, a circled
jdaggett@8356 4814 number glyph will be used:</p>
jdaggett@8356 4815
jdaggett@8356 4816 <pre>@font-feature-values Taisho Gothic {
jdaggett@7041 4817 @annotation { boxed: 1; circled: 4; }
jdaggett@2118 4818 }
jdaggett@2118 4819
jdaggett@2118 4820 @font-feature-values Otaru Kisa {
jdaggett@7041 4821 @annotation { circled: 1; black-boxed: 3; }
jdaggett@2118 4822 }
jdaggett@2118 4823
jdaggett@2118 4824 h3.title {
jdaggett@2118 4825 /* circled form defined for both fonts */
jdaggett@2118 4826 font-family: Taisho Gothic, Otaru Kisa;
jdaggett@2118 4827 font-variant: annotation(circled);
jdaggett@2118 4828 }</pre>
jdaggett@8356 4829 </div>
jdaggett@8356 4830
jdaggett@8356 4831 <h4 id=multi-valued-feature-value-definitions><span class=secno>6.9.2
jdaggett@8356 4832 </span>Multi-valued feature value definitions</h4>
jdaggett@8356 4833
jdaggett@8356 4834 <p>Most <a href="#font-specific"><em>font specific</em></a> ‘<a
jdaggett@8356 4835 href="#propdef-font-variant-alternates"><code
jdaggett@8356 4836 class=property>font-variant-alternates</code></a>’ property values take
jdaggett@8356 4837 a single value (e.g. ‘<a href="#swash"><code
jdaggett@8356 4838 class=property>swash</code></a>’). The ‘<a
jdaggett@8356 4839 href="#character-variant"><code
jdaggett@8356 4840 class=property>character-variant</code></a>’ property value allows two
jdaggett@8356 4841 values and ‘<a href="#styleset"><code
jdaggett@8356 4842 class=property>styleset</code></a>’ allows an unlimited number.
jdaggett@3571 4843
jdaggett@3571 4844 <p>For the styleset property value, multiple values indicate the style sets
jdaggett@7095 4845 to be enabled. Values between 1 and 99 enable OpenType features <span
jdaggett@7095 4846 class=tag>ss01</span> through <span class=tag>ss99</span>. However, the
jdaggett@7095 4847 OpenType standard only officially defines <span class=tag>ss01</span>
jdaggett@8356 4848 through <span class=tag>ss20</span>. For OpenType fonts, values greater
jdaggett@8356 4849 than 99 or equal to 0 do not generate a syntax error when parsed but
jdaggett@8356 4850 enable no OpenType features.
jdaggett@2472 4851
jdaggett@2472 4852 <pre>@font-feature-values Mars Serif {
jdaggett@8277 4853 @styleset {
jdaggett@7041 4854 alt-g: 1; /* implies ss01 = 1 */
jdaggett@7041 4855 curly-quotes: 3; /* implies ss03 = 1 */
jdaggett@7041 4856 code: 4 5; /* implies ss04 = 1, ss05 = 1 */
jdaggett@7041 4857 }
jdaggett@7041 4858
jdaggett@7041 4859 @styleset {
jdaggett@7095 4860 dumb: 125; /* &gt;99, ignored */
jdaggett@7041 4861 }
jdaggett@7041 4862
jdaggett@7041 4863 @swash {
jdaggett@7041 4864 swishy: 3 5; /* more than 1 value for swash, syntax error */
jdaggett@7041 4865 }
jdaggett@2472 4866 }
jdaggett@2472 4867
jdaggett@2472 4868 p.codeblock {
jdaggett@2472 4869 /* implies ss03 = 1, ss04 = 1, ss05 = 1 */
jdaggett@2472 4870 font-variant-alternates: styleset(curly-quotes, code);
jdaggett@2472 4871 }</pre>
jdaggett@2472 4872
jdaggett@2472 4873 <p>For character-variant, a single value between 1 and 99 indicates the
jdaggett@6436 4874 enabling of OpenType feature <span class=tag>cv01</span> through <span
jdaggett@7095 4875 class=tag>cv99</span>. For OpenType fonts, values greater than 99 or equal
jdaggett@8356 4876 to 0 are ignored but do not generate a syntax error when parsed but enable
jdaggett@8356 4877 no OpenType features. When two values are listed, the first value
jdaggett@8356 4878 indicates the feature used and the second the value passed for that
jdaggett@8356 4879 feature. If more than two values are assigned to a given name, a syntax
jdaggett@8356 4880 error occurs and the entire <a href="#featurevaluedefinition"><i
jdaggett@8356 4881 title="feature_value_definition">feature value definition</i></a> is
jdaggett@8356 4882 ignored.
jdaggett@2472 4883
jdaggett@2472 4884 <pre>@font-feature-values MM Greek {
jdaggett@7041 4885 @character-variant { alpha-2: 1 2; } /* implies cv01 = 2 */
jdaggett@7041 4886 @character-variant { beta-3: 2 3; } /* implies cv02 = 3 */
jdaggett@8356 4887 @character-variant { epsilon: 5 3 6; } /* more than 2 values, syntax error, definition ignored */
jdaggett@7041 4888 @character-variant { gamma: 12; } /* implies cv12 = 1 */
jdaggett@7041 4889 @character-variant { zeta: 20 3; } /* implies cv20 = 3 */
jdaggett@7041 4890 @character-variant { zeta-2: 20 2; } /* implies cv20 = 2 */
jdaggett@7041 4891 @character-variant { silly: 105; } /* &gt;99, ignored */
jdaggett@7041 4892 @character-variant { dumb: 323 3; } /* &gt;99, ignored */
jdaggett@2472 4893 }
jdaggett@2472 4894
jdaggett@2472 4895 #title {
jdaggett@2472 4896 /* use the third alternate beta, first alternate gamma */
jdaggett@2472 4897 font-variant-alternates: character-variant(beta-3, gamma);
jdaggett@3571 4898 }
jdaggett@3571 4899
jdaggett@3571 4900 p {
jdaggett@3571 4901 /* zeta-2 follows zeta, implies cv20 = 2 */
jdaggett@3571 4902 font-variant-alternates: character-variant(zeta, zeta-2);
jdaggett@3571 4903 }
jdaggett@3571 4904
jdaggett@3571 4905 .special {
jdaggett@3571 4906 /* zeta follows zeta-2, implies cv20 = 3 */
jdaggett@3571 4907 font-variant-alternates: character-variant(zeta-2, zeta);
jdaggett@2472 4908 }</pre>
jdaggett@2472 4909
jdaggett@2472 4910 <div class=figure><img alt="Matching text on Byzantine seals using
jdaggett@2472 4911 character variants" src=byzantineseal.png>
jdaggett@2472 4912 <p class=caption>Byzantine seal text displayed with character variants
jdaggett@2472 4913 </div>
jdaggett@2472 4914
jdaggett@2472 4915 <div class=example>
jdaggett@2472 4916 <p>In the figure above, the text in red is rendered using a font
jdaggett@2472 4917 containing character variants that mimic the character forms found on a
jdaggett@2472 4918 Byzantine seal from the 8th century A.D. Two lines below is the same text
jdaggett@2472 4919 displayed in a font without variants. Note the two variants for U and N
jdaggett@2509 4920 used on the seal.</p>
jdaggett@2472 4921
jdaggett@2472 4922 <pre>@font-feature-values Athena Ruby {
jdaggett@7041 4923 @character-variant {
jdaggett@7041 4924 leo-B: 2 1;
jdaggett@7041 4925 leo-M: 13 3;
jdaggett@7041 4926 leo-alt-N: 14 1;
jdaggett@7041 4927 leo-N: 14 2;
jdaggett@8277 4928 leo-T: 20 1;
jdaggett@7041 4929 leo-U: 21 2;
jdaggett@7041 4930 leo-alt-U: 21 4;
jdaggett@7041 4931 }
jdaggett@2472 4932 }
jdaggett@2472 4933
jdaggett@2472 4934 p {
jdaggett@6653 4935 font-variant: discretionary-ligatures,
jdaggett@6653 4936 character-variant(leo-B, leo-M, leo-N, leo-T, leo-U);
jdaggett@2472 4937 }
jdaggett@2472 4938
jdaggett@8277 4939 span.alt-N {
jdaggett@2472 4940 font-variant-alternates: character-variant(leo-alt-N);
jdaggett@2472 4941 }
jdaggett@2472 4942
jdaggett@2472 4943 span.alt-U {
jdaggett@2472 4944 font-variant-alternates: character-variant(leo-alt-U);
jdaggett@2472 4945 }
jdaggett@2472 4946
jdaggett@2472 4947 &lt;p>ENO....UP͞RSTU&lt;span class="alt-U">U&lt;/span>͞&lt;span class="alt-U">U&lt;/span>ΚΑΙTỤẠG̣IUPNS&lt;/p>
jdaggett@2472 4948
jdaggett@8277 4949 &lt;p>LEON|ΚΑΙCONSTA|NTI&lt;span class="alt-N">N&lt;/span>OS..|STOIBAṢ.|LIṢROM|AIO&lt;span class="alt-N">N&lt;/span>&lt;/p>
jdaggett@2472 4950 </pre>
jdaggett@2118 4951 </div>
jdaggett@2118 4952
jdaggett@2118 4953 <h3 id=font-variant-east-asian-prop><span class=secno>6.10 </span>East
jdaggett@2118 4954 Asian text rendering: the <a
jdaggett@1662 4955 href="#propdef-font-variant-east-asian">font-variant-east-asian</a>
jdaggett@1662 4956 property</h3>
jdaggett@1662 4957
jdaggett@5809 4958 <table class=propdef id=namefont-variant-east-asianvaluenormal-l>
jdaggett@1662 4959 <tbody>
jdaggett@1662 4960 <tr>
jdaggett@1662 4961 <td>Name:
jdaggett@1662 4962
jdaggett@1662 4963 <td><dfn
jdaggett@1662 4964 id=propdef-font-variant-east-asian>font-variant-east-asian</dfn>
jdaggett@1662 4965
jdaggett@1662 4966 <tr>
jdaggett@1662 4967 <td>Value:
jdaggett@1662 4968
jdaggett@8278 4969 <td><a href="#font-variant-east-asian-normal-value"
jdaggett@8278 4970 title="normal!!font-variant-east-asian">normal</a> | [ <a
jdaggett@8225 4971 href="#east-asian-variant-values"><var>&lt;east-asian-variant-values&gt;</var></a>
jdaggett@8225 4972 || <a
jdaggett@8225 4973 href="#east-asian-width-values"><var>&lt;east-asian-width-values&gt;</var></a>
jdaggett@8225 4974 || <a href="#ruby">ruby</a> ]
jdaggett@1662 4975
jdaggett@1662 4976 <tr>
jdaggett@1662 4977 <td>Initial:
jdaggett@1662 4978
jdaggett@1662 4979 <td>normal
jdaggett@1662 4980
jdaggett@1662 4981 <tr>
jdaggett@1662 4982 <td>Applies to:
jdaggett@1662 4983
jdaggett@1662 4984 <td>all elements
jdaggett@1662 4985
jdaggett@1662 4986 <tr>
jdaggett@1662 4987 <td>Inherited:
jdaggett@1662 4988
jdaggett@1662 4989 <td>yes
jdaggett@1662 4990
jdaggett@1662 4991 <tr>
jdaggett@1662 4992 <td>Percentages:
jdaggett@1662 4993
jdaggett@1662 4994 <td>N/A
jdaggett@1662 4995
jdaggett@1662 4996 <tr>
jdaggett@1662 4997 <td>Media:
jdaggett@1662 4998
jdaggett@1662 4999 <td>visual
jdaggett@1662 5000
jdaggett@1662 5001 <tr>
jdaggett@1662 5002 <td>Computed value:
jdaggett@1662 5003
jdaggett@1662 5004 <td>as specified
jdaggett@7377 5005
jdaggett@7377 5006 <tr>
jdaggett@7377 5007 <td>Animatable:
jdaggett@7377 5008
jdaggett@7377 5009 <td>no
jdaggett@1662 5010 </table>
jdaggett@1662 5011
jdaggett@6693 5012 <p>Allows control of glyph substitution and sizing in East Asian text.
jdaggett@1662 5013
jdaggett@1662 5014 <pre
jdaggett@8225 5015 class=prod><dfn id=east-asian-variant-values><var>&lt;east-asian-variant-values&gt;</var></dfn> = [ <a href="#jis78">jis78</a> | <a href="#jis83">jis83</a> | <a href="#jis90">jis90</a> | <a href="#jis04">jis04</a> | <a href="#simplified">simplified</a> | <a href="#traditional">traditional</a> ]</pre>
jdaggett@1662 5016
jdaggett@1662 5017 <pre
jdaggett@8225 5018 class=prod><dfn id=east-asian-width-values><var>&lt;east-asian-width-values&gt;</var></dfn> = [ <a href="#full-width">full-width</a> | <a href="#proportional-width">proportional-width</a> ]</pre>
jdaggett@1732 5019
jdaggett@1732 5020 <p>Individual values have the following meanings:
jdaggett@1662 5021
jdaggett@1662 5022 <dl>
jdaggett@8278 5023 <dt><dfn id=font-variant-east-asian-normal-value
jdaggett@8278 5024 title="normal!!font-variant-east-asian">normal</dfn>
jdaggett@5809 5025
jdaggett@5809 5026 <dd>None of the features listed below are enabled.
jdaggett@5809 5027
jdaggett@1662 5028 <dt><dfn id=jis78>jis78</dfn>
jdaggett@1662 5029
jdaggett@6436 5030 <dd>Enables rendering of JIS78 forms (OpenType feature: <span
jdaggett@6436 5031 class=tag>jp78</span>).
jdaggett@1662 5032 </dl>
jdaggett@1662 5033
jdaggett@1662 5034 <div class=featex><img alt="JIS78 form example" src=jp78.png></div>
jdaggett@1662 5035
jdaggett@1662 5036 <dl>
jdaggett@1662 5037 <dt><dfn id=jis83>jis83</dfn>
jdaggett@1662 5038
jdaggett@6436 5039 <dd>Enables rendering of JIS83 forms (OpenType feature: <span
jdaggett@6436 5040 class=tag>jp83</span>).
jdaggett@1662 5041
jdaggett@1662 5042 <dt><dfn id=jis90>jis90</dfn>
jdaggett@1662 5043
jdaggett@6436 5044 <dd>Enables rendering of JIS90 forms (OpenType feature: <span
jdaggett@6436 5045 class=tag>jp90</span>).
jdaggett@1662 5046
jdaggett@1662 5047 <dt><dfn id=jis04>jis04</dfn>
jdaggett@1662 5048
jdaggett@6436 5049 <dd>Enables rendering of JIS2004 forms (OpenType feature: <span
jdaggett@6436 5050 class=tag>jp04</span>).
jdaggett@6693 5051 <p>The various JIS variants reflect the glyph forms defined in different
jdaggett@6693 5052 Japanese national standards. Fonts generally include glyphs defined by
jdaggett@6693 5053 the most recent national standard but it's sometimes necessary to use
jdaggett@6693 5054 older variants, to match signage for example.</p>
jdaggett@1662 5055
jdaggett@2504 5056 <dt><dfn id=simplified>simplified</dfn>
jdaggett@2504 5057
jdaggett@6436 5058 <dd>Enables rendering of simplified forms (OpenType feature: <span
jdaggett@6436 5059 class=tag>smpl</span>).
jdaggett@2504 5060
jdaggett@2504 5061 <dt><dfn id=traditional>traditional</dfn>
jdaggett@2504 5062
jdaggett@6436 5063 <dd>Enables rendering of traditional forms (OpenType feature: <span
jdaggett@6436 5064 class=tag>trad</span>).
jdaggett@1662 5065 </dl>
jdaggett@1662 5066
jdaggett@8312 5067 <p>The ‘<a href="#simplified"><code
jdaggett@8312 5068 class=property>simplified</code></a>’ and ‘<a
jdaggett@8312 5069 href="#traditional"><code class=property>traditional</code></a>’ values
jdaggett@8312 5070 allow control over the glyph forms for characters which have been
jdaggett@8312 5071 simplified over time but for which the older, traditional form is still
jdaggett@8312 5072 used in some contexts. The exact set of characters and glyph forms will
jdaggett@8312 5073 vary to some degree by context for which a given font was designed.
jdaggett@8312 5074
jdaggett@1662 5075 <div class=featex><img alt="tradtional form example" src=trad.png></div>
jdaggett@1662 5076
jdaggett@1662 5077 <dl>
jdaggett@1662 5078 <dt><dfn id=full-width>full-width</dfn>
jdaggett@1662 5079
jdaggett@6436 5080 <dd>Enables rendering of full-width variants (OpenType feature: <span
jdaggett@6436 5081 class=tag>fwid</span>).
jdaggett@1662 5082
jdaggett@1662 5083 <dt><dfn id=proportional-width>proportional-width</dfn>
jdaggett@1662 5084
jdaggett@1662 5085 <dd>Enables rendering of proportionally-spaced variants (OpenType feature:
jdaggett@6436 5086 <span class=tag>pwid</span>).
jdaggett@1662 5087 </dl>
jdaggett@1662 5088
jdaggett@1662 5089 <div class=featex><img alt="proportionally spaced Japanese example"
jdaggett@1662 5090 src=pwid.png></div>
jdaggett@1662 5091
jdaggett@3638 5092 <dl>
jdaggett@3638 5093 <dt><dfn id=ruby>ruby</dfn>
jdaggett@3638 5094
jdaggett@6436 5095 <dd>Enables display of ruby variant glyphs (OpenType feature: <span
jdaggett@6436 5096 class=tag>ruby</span>). Since ruby text is generally smaller than the
jdaggett@3638 5097 associated body text, font designers can design special glyphs for use
jdaggett@3638 5098 with ruby that are more readable than scaled down versions of the default
jdaggett@3638 5099 glyphs. Only glyph selection is affected, there is no associated font
jdaggett@3638 5100 scaling or other change that affects line layout. The red ruby text below
jdaggett@3638 5101 is shown with default glyphs (top) and with ruby variant glyphs (bottom).
jdaggett@3638 5102 Note the slight difference in stroke thickness.
jdaggett@3638 5103 </dl>
jdaggett@3638 5104
jdaggett@3638 5105 <div class=featex><img alt="ruby variant example" src=rubyshinkansen.png></div>
jdaggett@3638 5106
jdaggett@2118 5107 <h3 id=font-variant-prop><span class=secno>6.11 </span>Overall shorthand
jdaggett@1856 5108 for font rendering: the <a href="#propdef-font-variant">font-variant</a>
jdaggett@1662 5109 property</h3>
jdaggett@1662 5110
jdaggett@6436 5111 <table class=propdef id=namefont-variantvaluenormal-none-ltcommo>
jdaggett@1662 5112 <tbody>
jdaggett@1662 5113 <tr>
jdaggett@1662 5114 <td>Name:
jdaggett@1662 5115
jdaggett@8278 5116 <td><dfn id=propdef-font-variant
jdaggett@8278 5117 title="font-variant!!property">font-variant</dfn>
jdaggett@1662 5118
jdaggett@1662 5119 <tr>
jdaggett@1662 5120 <td>Value:
jdaggett@1662 5121
jdaggett@8278 5122 <td><a href="#font-variant-normal-value"
jdaggett@8278 5123 title="normal!!font-variant">normal</a> | <a
jdaggett@8278 5124 href="#font-variant-none-value" title="none!!font-variant">none</a> | [
jdaggett@8278 5125 <a href="#common-lig-values"><var>&lt;common-lig-values&gt;</var></a>
jdaggett@8278 5126 || <a
jdaggett@8225 5127 href="#discretionary-lig-values"><var>&lt;discretionary-lig-values&gt;</var></a>
jdaggett@8225 5128 || <a
jdaggett@8225 5129 href="#historical-lig-values"><var>&lt;historical-lig-values&gt;</var></a>
jdaggett@8225 5130 || <a
jdaggett@8225 5131 href="#contextual-alt-values"><var>&lt;contextual-alt-values&gt;</var></a>
jdaggett@8225 5132 || <a href="#stylistic"><var
jdaggett@8225 5133 title=stylistic>stylistic(&lt;feature-value-name&gt;)</var></a> || <a
jdaggett@8225 5134 href="#historical-forms"><var>historical-forms</var></a> || <a
jdaggett@8225 5135 href="#styleset"><var
jdaggett@8225 5136 title=styleset>styleset(&lt;feature-value-name&gt; #)</var></a> || <a
jdaggett@8225 5137 href="#character-variant"><var
jdaggett@8225 5138 title=character-variant>character-variant(&lt;feature-value-name&gt;
jdaggett@8225 5139 #)</var></a> || <a href="#swash"><var
jdaggett@8225 5140 title=swash>swash(&lt;feature-value-name&gt;)</var></a> || <a
jdaggett@8225 5141 href="#ornaments"><var
jdaggett@8225 5142 title=ornaments>ornaments(&lt;feature-value-name&gt;)</var></a> || <a
jdaggett@8225 5143 href="#annotation"><var
jdaggett@8225 5144 title=annotation>annotation(&lt;feature-value-name&gt;)</var></a> || [
jdaggett@8225 5145 <a href="#small-caps"><i>small-caps</i></a> | <a
jdaggett@8225 5146 href="#all-small-caps"><i>all-small-caps</i></a> | <a
jdaggett@8225 5147 href="#petite-caps"><i>petite-caps</i></a> | <a
jdaggett@8225 5148 href="#all-petite-caps"><i>all-petite-caps</i></a> | <a
jdaggett@8225 5149 href="#unicase"><i>unicase</i></a> | <a
jdaggett@8225 5150 href="#titling-caps"><i>titling-caps</i></a> ] || <a
jdaggett@8225 5151 href="#numeric-figure-values"><var>&lt;numeric-figure-values&gt;</var></a>
jdaggett@8225 5152 || <a
jdaggett@8225 5153 href="#numeric-spacing-values"><var>&lt;numeric-spacing-values&gt;</var></a>
jdaggett@8225 5154 || <a
jdaggett@8225 5155 href="#numeric-fraction-values"><var>&lt;numeric-fraction-values&gt;</var></a>
jdaggett@8225 5156 || <a href="#ordinal"><i>ordinal</i></a> || <a
jdaggett@8225 5157 href="#slashed-zero"><i>slashed-zero</i></a> || <a
jdaggett@8225 5158 href="#east-asian-variant-values"><var>&lt;east-asian-variant-values&gt;</var></a>
jdaggett@8225 5159 || <a
jdaggett@8225 5160 href="#east-asian-width-values"><var>&lt;east-asian-width-values&gt;</var></a>
jdaggett@8225 5161 || <a href="#ruby"><i>ruby</i></a> ]
jdaggett@1662 5162
jdaggett@1662 5163 <tr>
jdaggett@1662 5164 <td>Initial:
jdaggett@1662 5165
jdaggett@1662 5166 <td>normal
jdaggett@1662 5167
jdaggett@1662 5168 <tr>
jdaggett@1662 5169 <td>Applies to:
jdaggett@1662 5170
jdaggett@1662 5171 <td>all elements
jdaggett@1662 5172
jdaggett@1662 5173 <tr>
jdaggett@1662 5174 <td>Inherited:
jdaggett@1662 5175
jdaggett@1662 5176 <td>yes
jdaggett@1662 5177
jdaggett@1662 5178 <tr>
jdaggett@1662 5179 <td>Percentages:
jdaggett@1662 5180
jdaggett@7377 5181 <td>see individual properties
jdaggett@1662 5182
jdaggett@1662 5183 <tr>
jdaggett@1662 5184 <td>Media:
jdaggett@1662 5185
jdaggett@1662 5186 <td>visual
jdaggett@1662 5187
jdaggett@1662 5188 <tr>
jdaggett@1662 5189 <td>Computed value:
jdaggett@1662 5190
jdaggett@7377 5191 <td>see individual properties
jdaggett@7377 5192
jdaggett@7377 5193 <tr>
jdaggett@7377 5194 <td>Animatable:
jdaggett@7377 5195
jdaggett@7377 5196 <td>see individual properties
jdaggett@1662 5197 </table>
jdaggett@1662 5198
jdaggett@8313 5199 <p>The <a href="#propdef-font-variant"
jdaggett@8313 5200 title="font-variant!!property">‘<code
jdaggett@8313 5201 class=property>font-variant</code>’</a> property is a shorthand for all
jdaggett@8313 5202 font-variant subproperties. The value <dfn id=font-variant-normal-value
jdaggett@8313 5203 title="normal!!font-variant">‘<code
jdaggett@8313 5204 class=property>normal</code>’</dfn> resets all subproperties of <a
jdaggett@8313 5205 href="#propdef-font-variant" title="font-variant!!property">‘<code
jdaggett@8313 5206 class=property>font-variant</code>’</a> to their inital value. The <dfn
jdaggett@8313 5207 id=font-variant-none-value title="none!!font-variant">‘<code
jdaggett@8313 5208 class=property>none</code>’</dfn> value sets ‘<a
jdaggett@8313 5209 href="#propdef-font-variant-ligatures"><code
jdaggett@8278 5210 class=property>font-variant-ligatures</code></a>’ to ‘<code
jdaggett@8278 5211 class=property>none</code>’ and resets all other font feature properties
jdaggett@8278 5212 to their initial value. Like other shorthands, using <a
jdaggett@8278 5213 href="#propdef-font-variant" title="font-variant!!property">‘<code
jdaggett@8313 5214 class=property>font-variant</code>’</a> resets unspecified <a
jdaggett@8313 5215 href="#propdef-font-variant" title="font-variant!!property">‘<code
jdaggett@8313 5216 class=property>font-variant</code>’</a> subproperties to their initial
jdaggett@8313 5217 values. It does not reset the values of either ‘<a
jdaggett@8313 5218 href="#propdef-font-language-override"><code
jdaggett@8279 5219 class=property>font-language-override</code></a>’ or <a
jdaggett@8279 5220 href="#propdef-font-feature-settings"
jdaggett@8279 5221 title="font-feature-settings!!property">‘<code
jdaggett@8279 5222 class=property>font-feature-settings</code>’</a>.
jdaggett@1662 5223
jdaggett@2118 5224 <h3 id=font-feature-settings-prop><span class=secno>6.12 </span>Low-level
jdaggett@2509 5225 font feature settings control: the <a
jdaggett@1662 5226 href="#propdef-font-feature-settings">font-feature-settings</a> property</h3>
jdaggett@1662 5227
jdaggett@4624 5228 <table class=propdef id=namefont-feature-settingsvaluenormal-ltf>
jdaggett@1662 5229 <tbody>
jdaggett@1662 5230 <tr>
jdaggett@1662 5231 <td>Name:
jdaggett@1662 5232
jdaggett@8279 5233 <td><dfn id=propdef-font-feature-settings
jdaggett@8279 5234 title="font-feature-settings!!property">font-feature-settings</dfn>
jdaggett@1662 5235
jdaggett@1662 5236 <tr>
jdaggett@1662 5237 <td>Value:
jdaggett@1662 5238
jdaggett@8278 5239 <td><a href="#font-feature-settings-normal-value"
jdaggett@8278 5240 title="normal!!font-feature-settings">normal</a> | <a
jdaggett@8225 5241 href="#feature-tag-value"><var>&lt;feature-tag-value&gt;</var></a> #
jdaggett@1662 5242
jdaggett@1662 5243 <tr>
jdaggett@1662 5244 <td>Initial:
jdaggett@1662 5245
jdaggett@1662 5246 <td>normal
jdaggett@1662 5247
jdaggett@1662 5248 <tr>
jdaggett@1662 5249 <td>Applies to:
jdaggett@1662 5250
jdaggett@1662 5251 <td>all elements
jdaggett@1662 5252
jdaggett@1662 5253 <tr>
jdaggett@1662 5254 <td>Inherited:
jdaggett@1662 5255
jdaggett@1662 5256 <td>yes
jdaggett@1662 5257
jdaggett@1662 5258 <tr>
jdaggett@1662 5259 <td>Percentages:
jdaggett@1662 5260
jdaggett@1662 5261 <td>N/A
jdaggett@1662 5262
jdaggett@1662 5263 <tr>
jdaggett@1662 5264 <td>Media:
jdaggett@1662 5265
jdaggett@1662 5266 <td>visual
jdaggett@1662 5267
jdaggett@1662 5268 <tr>
jdaggett@1662 5269 <td>Computed value:
jdaggett@1662 5270
jdaggett@1662 5271 <td>as specified
jdaggett@7377 5272
jdaggett@7377 5273 <tr>
jdaggett@7377 5274 <td>Animatable:
jdaggett@7377 5275
jdaggett@7377 5276 <td>no
jdaggett@1662 5277 </table>
jdaggett@2474 5278
jdaggett@2474 5279 <p>This property provides low-level control over OpenType font features. It
jdaggett@2474 5280 is intended as a way of providing access to font features that are not
jdaggett@8312 5281 widely used but are needed for a particular use case.
jdaggett@8312 5282
jdaggett@8312 5283 <p>Authors should generally use <a href="#propdef-font-variant"
jdaggett@8312 5284 title="font-variant!!property">‘<code
jdaggett@8312 5285 class=property>font-variant</code>’</a> and its related subproperties
jdaggett@8312 5286 whenever possible and only use this property for special cases where its
jdaggett@8312 5287 use is the only way of accessing a particular infrequently used font
jdaggett@8312 5288 feature.
jdaggett@8312 5289
jdaggett@8312 5290 <pre>/* enable small caps and use second swash alternate */
jdaggett@8312 5291 font-feature-settings: "smcp", "swsh" 2;</pre>
jdaggett@8312 5292
jdaggett@8312 5293 <p>A value of <dfn id=font-feature-settings-normal-value
jdaggett@8278 5294 title="normal!!font-feature-settings">‘<code
jdaggett@8278 5295 class=property>normal</code>’</dfn> means that no change in glyph
jdaggett@8278 5296 selection or positioning occurs due to this property.
jdaggett@2474 5297
jdaggett@2509 5298 <p>Feature tag values have the following syntax:
jdaggett@2474 5299
jdaggett@2474 5300 <pre
jdaggett@8225 5301 class=prod><dfn id=feature-tag-value><var>&lt;feature-tag-value&gt;</var></dfn> = &lt;string&gt; [ &lt;integer&gt; | on | off ]?</pre>
jdaggett@2509 5302
jdaggett@5532 5303 <p>The &lt;string&gt; is a case-sensitive OpenType feature tag. As
jdaggett@5532 5304 specified in the OpenType specification, feature tags contain four ASCII
jdaggett@5532 5305 characters. Tag strings longer or shorter than four characters, or
jdaggett@5596 5306 containing characters outside the U+20–7E codepoint range are invalid.
jdaggett@8312 5307 Feature tags need only match a feature tag defined in the font, so they
jdaggett@8312 5308 are not limited to explicitly registered OpenType features. Fonts defining
jdaggett@8312 5309 custom feature tags should follow the <a
jdaggett@2474 5310 href="http://www.microsoft.com/typography/otspec/featuretags.htm">tag name
jdaggett@2474 5311 rules</a> defined in the OpenType specification <a
jdaggett@1662 5312 href="#OPENTYPE-FEATURES"
jdaggett@2474 5313 rel=biblioentry>[OPENTYPE-FEATURES]<!--{{!OPENTYPE-FEATURES}}--></a>.
jdaggett@8927 5314
jdaggett@8927 5315 <p>Feature tags not present in the font are ignored; a user agent must not
jdaggett@8927 5316 attempt to synthesize fallback behavior based on these feature tags. The
jdaggett@8927 5317 one exception is that user agents may synthetically support the <span
jdaggett@8927 5318 class=tag>kern</span> feature with fonts that contain kerning data in the
jdaggett@8927 5319 form of a ‘<code class=property>kern</code>’ table but lack <span
jdaggett@8927 5320 class=tag>kern</span> feature support in the ‘<code
jdaggett@8927 5321 class=property>GPOS</code>’ table.
jdaggett@8927 5322
jdaggett@8927 5323 <p class=note>In general, authors should use the ‘<a
jdaggett@5946 5324 href="#propdef-font-kerning"><code
jdaggett@8927 5325 class=property>font-kerning</code></a>’ property to explicitly enable or
jdaggett@8927 5326 disable kerning since this property always affects fonts with either type
jdaggett@8927 5327 of kerning data.
jdaggett@5946 5328
jdaggett@2509 5329 <p>If present, a value indicates an index used for glyph selection. An
jdaggett@2509 5330 &lt;integer&gt; value must be 0 or greater. A value of 0 indicates that
jdaggett@2509 5331 the feature is disabled. For boolean features, a value of 1 enables the
jdaggett@2509 5332 feature. For non-boolean features, a value of 1 or greater enables the
jdaggett@2509 5333 feature and indicates the feature selection index. A value of ‘<code
jdaggett@2509 5334 class=property>on</code>’ is synonymous with 1 and ‘<code
jdaggett@2509 5335 class=property>off</code>’ is synonymous with 0. If the value is
jdaggett@2509 5336 omitted, a value of 1 is assumed.
jdaggett@2474 5337
jdaggett@2474 5338 <pre>
jdaggett@2509 5339 font-feature-settings: "dlig" 1; /* dlig=1 enable discretionary ligatures */
jdaggett@2509 5340 font-feature-settings: "smcp" on; /* smcp=1 enable small caps */
jdaggett@2515 5341 font-feature-settings: 'c2sc'; /* c2sc=1 enable caps to small caps */
jdaggett@2509 5342 font-feature-settings: "liga" off; /* liga=0 no common ligatures */
jdaggett@2515 5343 font-feature-settings: "tnum", 'hist'; /* tnum=1, hist=1 enable tabular numbers and historical forms */
jdaggett@5530 5344 font-feature-settings: "tnum" "hist"; /* invalid, need a comma-delimited list */
jdaggett@8859 5345 font-feature-settings: "silly" off; /* invalid, tag too long */
jdaggett@2509 5346 font-feature-settings: "PKRN"; /* PKRN=1 enable custom feature */
jdaggett@5530 5347 font-feature-settings: dlig; /* invalid, tag must be a string */
jdaggett@2474 5348 </pre>
jdaggett@1662 5349
jdaggett@8272 5350 <p>When values greater than the range supported by the font are specified,
jdaggett@8272 5351 the behavior is explicitly undefined. For boolean features, in general
jdaggett@8272 5352 these will enable the feature. For non-boolean features, out of range
jdaggett@8272 5353 values will in general be equivalent to a 0 value. However, in both cases
jdaggett@8272 5354 the exact behavior will depend upon the way the font is designed
jdaggett@8272 5355 (specifically, which type of lookup is used to define the feature).
jdaggett@8272 5356
jdaggett@2474 5357 <p>Although specifically defined for OpenType feature tags, feature tags
jdaggett@2474 5358 for other modern font formats that support font features may be added in
jdaggett@5530 5359 the future. Where possible, features defined for other font formats should
jdaggett@5530 5360 attempt to follow the pattern of registered OpenType tags.
jdaggett@2509 5361
jdaggett@1662 5362 <div class=example>
jdaggett@1662 5363 <p>The Japanese text below will be rendered with half-width kana
jdaggett@1662 5364 characters:</p>
jdaggett@1662 5365
jdaggett@1662 5366 <pre lang=ja>
jdaggett@2509 5367 body { font-feature-settings: "hwid"; /* Half-width OpenType feature */ }
jdaggett@1662 5368
jdaggett@1662 5369 &lt;p>毎日<a href="http://images.google.com/images?q=%E3%82%AB%E3%83%AC%E3%83%BC" style="text-decoration: none;">カレー</a>食べてるのに、飽きない&lt;/p>
jdaggett@1662 5370 </pre>
jdaggett@1662 5371 </div>
jdaggett@1662 5372
jdaggett@2118 5373 <h3 id=font-language-override-prop><span class=secno>6.13 </span>Font
jdaggett@1732 5374 language override: the <a
jdaggett@1732 5375 href="#propdef-font-language-override">font-language-override</a> property</h3>
jdaggett@1732 5376
jdaggett@5809 5377 <table class=propdef id=namefont-language-overridevaluenormal-lt>
jdaggett@1662 5378 <tbody>
jdaggett@1662 5379 <tr>
jdaggett@1662 5380 <td>Name:
jdaggett@1662 5381
jdaggett@1732 5382 <td><dfn id=propdef-font-language-override>font-language-override</dfn>
jdaggett@1662 5383
jdaggett@1662 5384 <tr>
jdaggett@1662 5385 <td>Value:
jdaggett@1662 5386
jdaggett@8278 5387 <td><a href="#font-language-override-normal-value"
jdaggett@8278 5388 title="normal!!font-language-override">normal</a> | <a
jdaggett@8278 5389 href="#font-language-override-string-value"><var>&lt;string&gt;</var></a>
jdaggett@1662 5390
jdaggett@1662 5391 <tr>
jdaggett@1662 5392 <td>Initial:
jdaggett@1662 5393
jdaggett@8278 5394 <td><a href="#font-language-override-normal-value"
jdaggett@8278 5395 title="normal!!font-language-override">normal</a>
jdaggett@1662 5396
jdaggett@1662 5397 <tr>
jdaggett@1662 5398 <td>Applies to:
jdaggett@1662 5399
jdaggett@1662 5400 <td>all elements
jdaggett@1662 5401
jdaggett@1662 5402 <tr>
jdaggett@1662 5403 <td>Inherited:
jdaggett@1662 5404
jdaggett@1662 5405 <td>yes
jdaggett@1662 5406
jdaggett@1662 5407 <tr>
jdaggett@1662 5408 <td>Percentages:
jdaggett@1662 5409
jdaggett@1662 5410 <td>N/A
jdaggett@1662 5411
jdaggett@1662 5412 <tr>
jdaggett@1662 5413 <td>Media:
jdaggett@1662 5414
jdaggett@1662 5415 <td>visual
jdaggett@1662 5416
jdaggett@1662 5417 <tr>
jdaggett@1662 5418 <td>Computed value:
jdaggett@1662 5419
jdaggett@1662 5420 <td>as specified
jdaggett@7377 5421
jdaggett@7377 5422 <tr>
jdaggett@7377 5423 <td>Animatable:
jdaggett@7377 5424
jdaggett@7377 5425 <td>no
jdaggett@1662 5426 </table>
jdaggett@1662 5427
jdaggett@8278 5428 <p>Normally, authors can control the use of language-specific glyph
jdaggett@8278 5429 substitutions and positioning by setting the content language of an
jdaggett@8278 5430 element, as <a href="#language-specific-support">described above</a>:
jdaggett@8278 5431
jdaggett@8278 5432 <pre>&lt;!-- Display text using S'gaw Karen specific features -->
jdaggett@8387 5433 &lt;p lang="ksw">...&lt;/p></pre>
jdaggett@8278 5434
jdaggett@8278 5435 <p>In some cases, authors may need to specify a language system that
jdaggett@8278 5436 differs from the content language, for example due to the need to mimic
jdaggett@8278 5437 another language's typographic traditions. The ‘<a
jdaggett@8278 5438 href="#propdef-font-language-override"><code
jdaggett@8278 5439 class=property>font-language-override</code></a>’ property allows
jdaggett@8278 5440 authors to explicitly specify the language system of the font, overriding
jdaggett@8278 5441 the language system implied by the content language.
jdaggett@8278 5442
jdaggett@8278 5443 <p>Values have the following meanings:
jdaggett@8278 5444
jdaggett@8278 5445 <dl>
jdaggett@8278 5446 <dt><dfn id=font-language-override-normal-value
jdaggett@8278 5447 title="normal!!font-language-override">normal</dfn>
jdaggett@8278 5448
jdaggett@8278 5449 <dd>specifies that when rendering with OpenType fonts, the content
jdaggett@8278 5450 language of the element is used to infer the OpenType language system
jdaggett@8278 5451
jdaggett@8278 5452 <dt><dfn
jdaggett@8278 5453 id=font-language-override-string-value><var>&lt;string&gt;</var></dfn>
jdaggett@8278 5454
jdaggett@8368 5455 <dd>single three-letter case-sensitive OpenType <a
jdaggett@8278 5456 href="http://www.microsoft.com/typography/otspec/languagetags.htm">language
jdaggett@8278 5457 system tag</a>, specifies the OpenType language system to be used instead
jdaggett@8278 5458 of the language system implied by the language of the element
jdaggett@8278 5459 </dl>
jdaggett@8385 5460 <!-- For this level, string represents a single language code, there's no concept of "fallback"
jdaggett@8385 5461 http://www.w3.org/2013/06/07-css-minutes.html#item04 -->
jdaggett@1662 5462
jdaggett@8312 5463 <p>Use of invalid OpenType language system tags must not generate a parse
jdaggett@8312 5464 error but must be ignored when doing glyph selection and placement.
jdaggett@8312 5465
jdaggett@1662 5466 <div class=example>
jdaggett@7179 5467 <p>The <a href="http://www.un.org/en/documents/udhr/index.shtml">Universal
jdaggett@1662 5468 Declaration of Human Rights</a> has been translated into a wide variety
jdaggett@1662 5469 of languages. In Turkish, Article 9 of this document might be marked up
jdaggett@1662 5470 as below:</p>
jdaggett@1662 5471
jdaggett@1662 5472 <pre lang=tr>&lt;body lang="tr">
jdaggett@1662 5473
jdaggett@1662 5474 &lt;h4>Madde 9&lt;/h4>
jdaggett@1662 5475 &lt;p>Hiç kimse keyfi olarak tutuklanamaz, alıkonulanamaz veya sürülemez.&lt;/p>
jdaggett@1662 5476 </pre>
jdaggett@1662 5477
jdaggett@1662 5478 <p>Here the user agent uses the value of the ‘<code
jdaggett@1662 5479 class=property>lang</code>’ attribute when rendering text and
jdaggett@1662 5480 appropriately renders this text without ‘<code
jdaggett@4624 5481 class=property>fi</code>’ ligatures. There is no need to use the ‘<a
jdaggett@4624 5482 href="#propdef-font-language-override"><code
jdaggett@4624 5483 class=property>font-language-override</code></a>’ property.</p>
jdaggett@1662 5484
jdaggett@1662 5485 <p>However, a given font may lack support for a specific language. In this
jdaggett@1662 5486 situation authors may need to use the typographic conventions of a
jdaggett@1662 5487 related language that are supported by that font:</p>
jdaggett@1662 5488
jdaggett@1662 5489 <pre lang=mk>&lt;body lang="mk"> &lt;!-- Macedonian lang code --&gt;
jdaggett@1662 5490
jdaggett@1732 5491 body { font-language-override: "SRB"; /* Serbian OpenType language tag */ }
jdaggett@1662 5492
jdaggett@1662 5493 &lt;h4>Члeн 9&lt;/h4>
jdaggett@1662 5494 &lt;p>Никoj чoвeк нeмa дa бидe пoдлoжeн нa прoизвoлнo aпсeњe, притвoр или прoгoнувaњe.&lt;/p>
jdaggett@1662 5495
jdaggett@1662 5496 </pre>
jdaggett@1662 5497
jdaggett@1662 5498 <p>The Macedonian text here will be rendered using Serbian typographic
jdaggett@1662 5499 conventions, with the assumption that the font specified supports
jdaggett@1662 5500 Serbian.</p>
jdaggett@1662 5501 </div>
jdaggett@1662 5502
jdaggett@6176 5503 <p><a id=rendering-considerations></a>
jdaggett@6176 5504
jdaggett@6699 5505 <h2 id=font-feature-resolution><span class=secno>7 </span>Font Feature
jdaggett@6699 5506 Resolution</h2>
jdaggett@6176 5507
jdaggett@6176 5508 <p>As described in the previous section, font features can be enabled in a
jdaggett@8278 5509 variety of ways, either via the use of <a href="#propdef-font-variant"
jdaggett@8278 5510 title="font-variant!!property">‘<code
jdaggett@8279 5511 class=property>font-variant</code>’</a> or <a
jdaggett@8279 5512 href="#propdef-font-feature-settings"
jdaggett@8279 5513 title="font-feature-settings!!property">‘<code
jdaggett@8279 5514 class=property>font-feature-settings</code>’</a> in a style rule or
jdaggett@8311 5515 within an <a href="#at-font-face-rule"><code>@font-face</code></a> rule.
jdaggett@8311 5516 The resolution order for the union of these settings is defined below.
jdaggett@8311 5517 Features defined via CSS properties are applied on top of layout engine
jdaggett@8311 5518 default features.
jdaggett@6176 5519
jdaggett@6699 5520 <h3 id=default-features><span class=secno>7.1 </span>Default features</h3>
jdaggett@6699 5521
jdaggett@6176 5522 <p>For OpenType fonts, user agents must enable the default features defined
jdaggett@6436 5523 in the OpenType documentation for a given script and writing mode.
jdaggett@6436 5524 Required ligatures, common ligatures and contextual forms must be enabled
jdaggett@6436 5525 by default (OpenType features: <span class=tag>rlig, liga, clig,
jdaggett@6436 5526 calt</span>), along with localized forms (OpenType feature: <span
jdaggett@6436 5527 class=tag>locl</span>), and features required for proper display of
jdaggett@6436 5528 composed characters and marks (OpenType features: <span class=tag>ccmp,
jdaggett@6436 5529 mark, mkmk</span>). These features must always be enabled, even when the
jdaggett@8278 5530 value of the <a href="#propdef-font-variant"
jdaggett@8278 5531 title="font-variant!!property">‘<code
jdaggett@8279 5532 class=property>font-variant</code>’</a> and <a
jdaggett@8279 5533 href="#propdef-font-feature-settings"
jdaggett@8279 5534 title="font-feature-settings!!property">‘<code
jdaggett@8368 5535 class=property>font-feature-settings</code>’</a> properties is <span
jdaggett@8368 5536 title="normal value">‘<code class=property>normal</code>’</span>.
jdaggett@8368 5537 Individual features are only disabled when explicitly overridden by the
jdaggett@8368 5538 author, as when ‘<a href="#propdef-font-variant-ligatures"><code
jdaggett@6176 5539 class=property>font-variant-ligatures</code></a>’ is set to ‘<a
jdaggett@6176 5540 href="#no-common-ligatures"><code
jdaggett@7377 5541 class=property>no-common-ligatures</code></a>’. For handling complex
jdaggett@7377 5542 scripts such as <a
jdaggett@6176 5543 href="http://www.microsoft.com/typography/otfntdev/arabicot/features.aspx">Arabic</a>,
jdaggett@6176 5544 <a
jdaggett@6176 5545 href="http://www.microsoft.com/typography/otfntdev/mongolot/features.htm">Mongolian</a>
jdaggett@6176 5546 or <a
jdaggett@6176 5547 href="http://www.microsoft.com/typography/otfntdev/devanot/features.aspx">Devanagari</a>
jdaggett@6436 5548 additional features are required. For upright text within vertical text
jdaggett@6436 5549 runs, vertical alternates (OpenType feature: <span class=tag>vert</span>)
jdaggett@6436 5550 must be enabled.
jdaggett@1662 5551
jdaggett@6699 5552 <h3 id=feature-precedence><span class=secno>7.2 </span>Feature precedence</h3>
jdaggett@6699 5553
jdaggett@8356 5554 <p>General and <a href="#font-specific"><em>font specific</em></a> font
jdaggett@8356 5555 feature property settings are resolved in the order below, in ascending
jdaggett@8360 5556 order of precedence. This ordering is used to construct a combined list of
jdaggett@8356 5557 font features that affect a given text run.
jdaggett@1662 5558
jdaggett@1662 5559 <ol>
jdaggett@6436 5560 <li>Font features enabled by default, including features required for a
jdaggett@6436 5561 given script.
jdaggett@6176 5562
jdaggett@8311 5563 <li>If the font is defined via an <a
jdaggett@8311 5564 href="#at-font-face-rule"><code>@font-face</code></a> rule, the font
jdaggett@8311 5565 features implied by the font-variant descriptor in the <a
jdaggett@8311 5566 href="#at-font-face-rule"><code>@font-face</code></a> rule.
jdaggett@8311 5567
jdaggett@8311 5568 <li>If the font is defined via an <a
jdaggett@8311 5569 href="#at-font-face-rule"><code>@font-face</code></a> rule, the font
jdaggett@8311 5570 features implied by the font-feature-settings descriptor in the <a
jdaggett@8311 5571 href="#at-font-face-rule"><code>@font-face</code></a> rule.
jdaggett@1662 5572
jdaggett@8804 5573 <li>Font features implied by the value of the <a
jdaggett@8804 5574 href="#propdef-font-variant" title="font-variant!!property">‘<code
jdaggett@8804 5575 class=property>font-variant</code>’</a> property, the related <a
jdaggett@8804 5576 href="#propdef-font-variant" title="font-variant!!property">‘<code
jdaggett@8804 5577 class=property>font-variant</code>’</a> subproperties and any other CSS
jdaggett@8804 5578 property that uses OpenType features (e.g. the ‘<a
jdaggett@8804 5579 href="#propdef-font-kerning"><code
jdaggett@8804 5580 class=property>font-kerning</code></a>’ property).</li>
jdaggett@8804 5581 <!-- other CSS props override 'font-variant' but not 'font-feature-settings' -->
jdaggett@8804 5582 <!-- http://lists.w3.org/Archives/Public/www-style/2013Aug/0110.html -->
jdaggett@8804 5583
jdaggett@8278 5584 <li>Feature settings determined by properties other than <a
jdaggett@8278 5585 href="#propdef-font-variant" title="font-variant!!property">‘<code
jdaggett@8279 5586 class=property>font-variant</code>’</a> or <a
jdaggett@8279 5587 href="#propdef-font-feature-settings"
jdaggett@8279 5588 title="font-feature-settings!!property">‘<code
jdaggett@8279 5589 class=property>font-feature-settings</code>’</a>. For example, setting
jdaggett@8279 5590 a non-default value for the ‘<code
jdaggett@8360 5591 class=property>letter-spacing</code>’ property disables common
jdaggett@8360 5592 ligatures.
jdaggett@6176 5593
jdaggett@8279 5594 <li>Font features implied by the value of <a
jdaggett@8279 5595 href="#propdef-font-feature-settings"
jdaggett@8279 5596 title="font-feature-settings!!property">‘<code
jdaggett@8279 5597 class=property>font-feature-settings</code>’</a> property.
jdaggett@1662 5598 </ol>
jdaggett@1662 5599
jdaggett@3511 5600 <p>This ordering allows authors to set up a general set of defaults for
jdaggett@8311 5601 fonts within their <a
jdaggett@8311 5602 href="#at-font-face-rule"><code>@font-face</code></a> rules, then override
jdaggett@8311 5603 them with property settings for specific elements. General property
jdaggett@8311 5604 settings override the settings in <a
jdaggett@8311 5605 href="#at-font-face-rule"><code>@font-face</code></a> rules and low-level
jdaggett@8311 5606 font feature settings override <a href="#propdef-font-variant"
jdaggett@8278 5607 title="font-variant!!property">‘<code
jdaggett@8278 5608 class=property>font-variant</code>’</a> property settings.
jdaggett@1732 5609
jdaggett@1732 5610 <p>For situations where the combined list of font feature settings contains
jdaggett@3511 5611 more than one value for the same feature, the last value is used. When a
jdaggett@3511 5612 font lacks support for a given underlying font feature, text is simply
jdaggett@3511 5613 rendered as if that font feature was not enabled; font fallback does not
jdaggett@3511 5614 occur and no attempt is made to synthesize the feature except where
jdaggett@8360 5615 explicitly defined for specific properties.
jdaggett@1662 5616
jdaggett@6699 5617 <h3 id=feature-precedence-examples><span class=secno>7.3 </span>Feature
jdaggett@6699 5618 precedence examples</h3>
jdaggett@6699 5619
jdaggett@1662 5620 <div class=example>
jdaggett@1662 5621 <p>With the styles below, numbers are rendered proportionally when used
jdaggett@1662 5622 within a paragraph but are shown in tabular form within tables of prices:</p>
jdaggett@1662 5623
jdaggett@8277 5624 <pre>body {
jdaggett@8277 5625 font-variant-numeric: proportional-nums;
jdaggett@1662 5626 }
jdaggett@1662 5627
jdaggett@1662 5628 table.prices td {
jdaggett@8277 5629 font-variant-numeric: tabular-nums;
jdaggett@1662 5630 }
jdaggett@1662 5631 </pre>
jdaggett@1662 5632 </div>
jdaggett@1662 5633
jdaggett@1662 5634 <div class=example>
jdaggett@8360 5635 <p>When the <a href="#descdef-font-variant"
jdaggett@8360 5636 title="font-variant!!descriptor">font-variant</a> descriptor is used
jdaggett@8360 5637 within an <a href="#at-font-face-rule"><code>@font-face</code></a> rule,
jdaggett@8360 5638 it only applies to the font defined by that rule.</p>
jdaggett@1662 5639
jdaggett@1662 5640 <pre>@font-face {
jdaggett@1662 5641 font-family: MainText;
jdaggett@8860 5642 src: url(http://example.com/font.woff);
jdaggett@1662 5643 font-variant: oldstyle-nums proportional-nums styleset(1,3);
jdaggett@1662 5644 }
jdaggett@1662 5645
jdaggett@1662 5646 body {
jdaggett@1662 5647 font-family: MainText, Helvetica;
jdaggett@1662 5648 }
jdaggett@1662 5649
jdaggett@1662 5650 table.prices td {
jdaggett@8277 5651 font-variant-numeric: tabular-nums;
jdaggett@1662 5652 }
jdaggett@1662 5653 </pre>
jdaggett@1662 5654
jdaggett@1662 5655 <p>In this case, old-style numerals will be used throughout but only where
jdaggett@1662 5656 the font "MainText" is used. Just as in the previous example, tabular
jdaggett@4624 5657 values will be used in price tables since ‘<a
jdaggett@4624 5658 href="#tabular-nums"><code class=property>tabular-nums</code></a>’
jdaggett@4624 5659 appears in a general style rule and its use is mutually exclusive with
jdaggett@4624 5660 ‘<a href="#proportional-nums"><code
jdaggett@4624 5661 class=property>proportional-nums</code></a>’. Stylistic alternate sets
jdaggett@4624 5662 will only be used where MainText is used.</p>
jdaggett@1662 5663 </div>
jdaggett@1662 5664
jdaggett@1662 5665 <div class=example>
jdaggett@8311 5666 <p>The <a href="#at-font-face-rule"><code>@font-face</code></a> rule can
jdaggett@8311 5667 also be used to access font features in locally available fonts via the
jdaggett@8311 5668 use of <code>local()</code> in the ‘<a href="#descdef-src"><code
jdaggett@8311 5669 class=property>src</code></a>’ descriptor of the <a
jdaggett@8311 5670 href="#at-font-face-rule"><code>@font-face</code></a> definition:</p>
jdaggett@1662 5671
jdaggett@1662 5672 <pre>@font-face {
jdaggett@1662 5673 font-family: BodyText;
jdaggett@1662 5674 src: local("HiraMaruPro-W4");
jdaggett@1662 5675 font-variant: proportional-width;
jdaggett@2509 5676 font-feature-settings: "ital"; /* Latin italics within CJK text feature */
jdaggett@1662 5677 }
jdaggett@1662 5678
jdaggett@1662 5679 body { font-family: BodyText, serif; }
jdaggett@1662 5680 </pre>
jdaggett@1662 5681
jdaggett@1662 5682 <p>If available, a Japanese font "Hiragino Maru Gothic" will be used. When
jdaggett@1662 5683 text rendering occurs, Japanese kana will be proportionally spaced and
jdaggett@1662 5684 Latin text will be italicised. Text rendered with the fallback serif font
jdaggett@1662 5685 will use default rendering properties.</p>
jdaggett@1662 5686 </div>
jdaggett@1662 5687
jdaggett@1662 5688 <div class=example>
jdaggett@3460 5689 <p>In the example below, discretionary ligatures are enabled only for a
jdaggett@1662 5690 downloadable font but are disabled within spans of class "special":</p>
jdaggett@1662 5691
jdaggett@1662 5692 <pre>@font-face {
jdaggett@1662 5693 font-family: main;
jdaggett@1662 5694 src: url(fonts/ffmeta.woff) format("woff");
jdaggett@3460 5695 font-variant: discretionary-ligatures;
jdaggett@1662 5696 }
jdaggett@1662 5697
jdaggett@1662 5698 body { font-family: main, Helvetica; }
jdaggett@3460 5699 span.special { font-variant-ligatures: no-discretionary-ligatures; }
jdaggett@1662 5700 </pre>
jdaggett@1662 5701
jdaggett@8360 5702 <p>Suppose one adds a rule using ‘<code
jdaggett@8360 5703 class=property>font-feature-settings</code>’ to enable discretionary
jdaggett@8360 5704 ligatures:</p>
jdaggett@1662 5705
jdaggett@1662 5706 <pre>body { font-family: main, Helvetica; }
jdaggett@2509 5707 span { font-feature-settings: "dlig"; }
jdaggett@3460 5708 span.special { font-variant-ligatures: no-discretionary-ligatures; }
jdaggett@1662 5709 </pre>
jdaggett@1662 5710
jdaggett@8360 5711 <p>In this case, discretionary ligatures <em>will</em> be rendered within
jdaggett@8360 5712 spans of class "special". This is because both the <a
jdaggett@8279 5713 href="#propdef-font-feature-settings"
jdaggett@8279 5714 title="font-feature-settings!!property">‘<code
jdaggett@8279 5715 class=property>font-feature-settings</code>’</a> and ‘<a
jdaggett@4624 5716 href="#propdef-font-variant-ligatures"><code
jdaggett@4624 5717 class=property>font-variant-ligatures</code></a>’ properties apply to
jdaggett@4624 5718 these spans. Although the ‘<code class=css>no-discretionary
jdaggett@4624 5719 ligatures</code>’ setting of ‘<a
jdaggett@4624 5720 href="#propdef-font-variant-ligatures"><code
jdaggett@4624 5721 class=property>font-variant-ligatures</code></a>’ effectively disables
jdaggett@8279 5722 the OpenType <span class=tag>dlig</span> feature, because the <a
jdaggett@8279 5723 href="#propdef-font-feature-settings"
jdaggett@8279 5724 title="font-feature-settings!!property">‘<code
jdaggett@8279 5725 class=property>font-feature-settings</code>’</a> is resolved after
jdaggett@8279 5726 that, the ‘<code class=property>dlig</code>’ value reenables
jdaggett@4624 5727 discretionary ligatures.</p>
jdaggett@1662 5728 </div>
jdaggett@1244 5729
jdaggett@7021 5730 <h2 id=object-model><span class=secno>8 </span>Object Model</h2>
jdaggett@7021 5731
jdaggett@8311 5732 <p>The contents of <a href="#at-font-face-rule"><code>@font-face</code></a>
jdaggett@8311 5733 and <a
jdaggett@8311 5734 href="#at-font-feature-values-rule"><code>@font-feature-values</code></a>
jdaggett@8311 5735 rules can be accessed via the following extensions to the CSS Object
jdaggett@8311 5736 Model.
jdaggett@7021 5737
jdaggett@7021 5738 <h3 id=om-fontface><span class=secno>8.1 </span>The <a
jdaggett@7021 5739 href="#cssfontfacerule"><code>CSSFontFaceRule</code></a> interface</h3>
jdaggett@7021 5740
jdaggett@7021 5741 <p>The <dfn id=cssfontfacerule>CSSFontFaceRule</dfn> interface represents a
jdaggett@8311 5742 <a href="#at-font-face-rule"><code>@font-face</code></a> rule.
jdaggett@7021 5743
jdaggett@7021 5744 <pre class=idl>
jdaggett@7021 5745 interface CSSFontFaceRule : CSSRule {
jdaggett@7041 5746 attribute DOMString family;
jdaggett@7041 5747 attribute DOMString src;
jdaggett@7041 5748 attribute DOMString style;
jdaggett@7041 5749 attribute DOMString weight;
jdaggett@7041 5750 attribute DOMString stretch;
jdaggett@7041 5751 attribute DOMString unicodeRange;
jdaggett@7041 5752 attribute DOMString variant;
jdaggett@7041 5753 attribute DOMString featureSettings;
jdaggett@7021 5754 }</pre>
jdaggett@7021 5755
jdaggett@7022 5756 <p>The DOM Level 2 Style specification <a href="#DOM-LEVEL-2-STYLE"
jdaggett@7022 5757 rel=biblioentry>[DOM-LEVEL-2-STYLE]<!--{{DOM-LEVEL-2-STYLE}}--></a>
jdaggett@7022 5758 defined a different variant of this rule. This definition supercedes that
jdaggett@7022 5759 one.
jdaggett@7021 5760
jdaggett@7021 5761 <h3 id=om-fontfeaturevalues><span class=secno>8.2 </span>The <a
jdaggett@7021 5762 href="#cssfontfeaturevaluesrule"><code>CSSFontFeatureValuesRule</code></a>
jdaggett@7021 5763 interface</h3>
jdaggett@7021 5764
jdaggett@7021 5765 <p>The <code>CSSRule</code> interface is extended as follows:
jdaggett@7021 5766
jdaggett@7021 5767 <pre class=idl>partial interface CSSRule {
jdaggett@7021 5768 const unsigned short FONT_FEATURE_VALUES_RULE = 14;
jdaggett@7021 5769 }</pre>
jdaggett@7021 5770
jdaggett@7021 5771 <p>The <dfn id=cssfontfeaturevaluesrule>CSSFontFeatureValuesRule</dfn>
jdaggett@8311 5772 interface represents a <a
jdaggett@8311 5773 href="#at-font-feature-values-rule"><code>@font-feature-values</code></a>
jdaggett@8311 5774 rule.
jdaggett@7021 5775
jdaggett@7021 5776 <pre class=idl>interface CSSFontFeatureValuesRule : CSSRule {
jdaggett@8640 5777 attribute DOMString fontFamily;
jdaggett@8640 5778 readonly attribute CSSFontFeatureValuesMap annotation;
jdaggett@8640 5779 readonly attribute CSSFontFeatureValuesMap ornaments;
jdaggett@8640 5780 readonly attribute CSSFontFeatureValuesMap stylistic;
jdaggett@8640 5781 readonly attribute CSSFontFeatureValuesMap swash;
jdaggett@8640 5782 readonly attribute CSSFontFeatureValuesMap characterVariant;
jdaggett@8640 5783 readonly attribute CSSFontFeatureValuesMap styleset;
jdaggett@8640 5784 }
jdaggett@8640 5785
jdaggett@8640 5786 [MapClass(DOMString, sequence&lt;unsigned long&gt;)]
jdaggett@8640 5787 interface CSSFontFeatureValuesMap {
jdaggett@8646 5788 void set(DOMString featureValueName,
jdaggett@8646 5789 (unsigned long or sequence&lt;unsigned long&gt;) values);
jdaggett@8640 5790 }</pre>
jdaggett@7021 5791
jdaggett@7021 5792 <dl class=idl-attributes>
jdaggett@8640 5793 <dt><var>fontFamily</var> of type <code>DOMString</code>
jdaggett@7021 5794
jdaggett@7021 5795 <dd>The list of one or more font families for which a given set of feature
jdaggett@7021 5796 values is defined.
jdaggett@7021 5797
jdaggett@8640 5798 <dt>value maps of type <code>CSSFontFeatureValuesMap</code>, readonly
jdaggett@8640 5799
jdaggett@8640 5800 <dd>Maps of feature values associated with feature value names for a given
jdaggett@8640 5801 ‘<a href="#propdef-font-variant-alternates"><code
jdaggett@8640 5802 class=property>font-variant-alternates</code></a>’ value type
jdaggett@7021 5803 </dl>
jdaggett@7021 5804
jdaggett@8640 5805 <p>Each value map attribute of <a
jdaggett@8640 5806 href="#cssfontfeaturevaluesrule"><code>CSSFontFeatureValuesRule</code></a>
jdaggett@8640 5807 reflects the values defined via a corresponding <a
jdaggett@8640 5808 href="#featurevalueblock"><i title="feature_value_block">feature value
jdaggett@8640 5809 block</i></a>. Thus, the <var title="annotation
jdaggett@8640 5810 attribute">annotation</var> attribute contains the values contained within
jdaggett@8640 5811 a <code title="@annotation">@annotation</code> <a
jdaggett@8640 5812 href="#featurevalueblock"><i title="feature_value_block">feature value
jdaggett@8640 5813 block</i></a>, the <var title="ornaments attribute">ornaments</var>
jdaggett@8640 5814 attribute contains the values contained with a <code
jdaggett@8640 5815 title="@ornaments">@ornaments</code> <a href="#featurevalueblock"><i
jdaggett@8640 5816 title="feature_value_block">feature value block</i></a> and so forth.
jdaggett@8640 5817
jdaggett@8654 5818 <p>The <code>CSSFontFeatureValuesMap</code> interface uses the <a
jdaggett@8655 5819 href="http://dev.w3.org/2006/webapi/WebIDL/#es-map-members">default map
jdaggett@8655 5820 class methods</a> but the <code>set</code> method has different behavior.
jdaggett@8655 5821 It takes a sequence of unsigned integers and associates it with a given
jdaggett@8654 5822 <code>featureValueName</code>. The method behaves the same as the default
jdaggett@8654 5823 map class method except that a single unsigned long value is treated as a
jdaggett@8654 5824 sequence of a single value. The method throws an exception if an invalid
jdaggett@8654 5825 number of values is passed in. If the associated <a
jdaggett@8654 5826 href="#featurevalueblock"><i title="feature_value_block">feature value
jdaggett@8640 5827 block</i></a> only allows a limited number of values, the <code>set</code>
jdaggett@8640 5828 method throws an <code>InvalidAccessError</code> exception when the input
jdaggett@8653 5829 sequence to <code>set</code> contains more than the limited number of
jdaggett@8653 5830 values. See the description of <a
jdaggett@8640 5831 href="#multi-valued-feature-value-definitions">multi-valued feature value
jdaggett@8640 5832 definitions</a> for details on the maximum number of values allowed for a
jdaggett@8640 5833 given type of <a href="#featurevalueblock"><i
jdaggett@8646 5834 title="feature_value_block">feature value block</i></a>. The
jdaggett@8653 5835 <code>get</code> method always returns a sequence of values, even if the
jdaggett@8653 5836 sequence only contains a single value.
jdaggett@8279 5837
jdaggett@2737 5838 <h2 class=no-num id=platform-props-to-css>Appendix A: Mapping platform font
jdaggett@1662 5839 properties to CSS properties</h2>
jdaggett@1662 5840
jdaggett@1662 5841 <p><em>This appendix is included as background for some of the problems and
jdaggett@890 5842 situations that are described in other sections. It should be viewed as
jdaggett@890 5843 informative only.</em>
jdaggett@890 5844
jdaggett@512 5845 <p>Font properties in CSS are designed to be independent of the underlying
jdaggett@512 5846 font formats used; they can be used to specify bitmap fonts, Type1 fonts,
jdaggett@890 5847 SVG fonts in addition to the common TrueType and OpenType fonts. But there
jdaggett@1244 5848 are facets of the TrueType and OpenType formats that often cause confusion
jdaggett@2556 5849 for authors and present challenges to implementers on different platforms.
jdaggett@1244 5850
jdaggett@1244 5851 <p>Originally developed at Apple, TrueType was designed as an outline font
jdaggett@1244 5852 format for both screen and print. Microsoft joined Apple in developing the
jdaggett@1244 5853 TrueType format and both platforms have supported TrueType fonts since
jdaggett@1244 5854 then. Font data in the TrueType format consists of a set of tables
jdaggett@1244 5855 distinguished with common four-letter tag names, each containing a
jdaggett@1244 5856 specific type of data. For example, naming information, including
jdaggett@1244 5857 copyright and license information, is stored in the ‘<code
jdaggett@7311 5858 class=property>name</code>’ table. The <a
jdaggett@7311 5859 href="#character-map"><em>character map</em></a> (‘<code
jdaggett@1244 5860 class=property>cmap</code>’) table contains a mapping of character
jdaggett@1244 5861 encodings to glyphs. Apple later added additional tables for supporting
jdaggett@1244 5862 enhanced typographic functionality; these are now called Apple Advanced
jdaggett@1244 5863 Typography, or AAT, fonts. Microsoft and Adobe developed a separate set of
jdaggett@1662 5864 tables for advanced typography and called their format OpenType <a
jdaggett@1662 5865 href="#OPENTYPE" rel=biblioentry>[OPENTYPE]<!--{{!OPENTYPE}}--></a>.
jdaggett@890 5866
jdaggett@890 5867 <p>In many cases the font data used under Microsoft Windows or Linux is
jdaggett@890 5868 slightly different from the data used under Apple's Mac OS X because the
jdaggett@6694 5869 TrueType format allowed for explicit variation across platforms. This
jdaggett@7311 5870 includes font metrics, names and <a href="#character-map"><em>character
jdaggett@7311 5871 map</em></a> data.
jdaggett@6694 5872
jdaggett@6694 5873 <p>Specifically, font family name data is handled differently across
jdaggett@6694 5874 platforms. For TrueType and OpenType fonts these names are contained in
jdaggett@6694 5875 the ‘<code class=property>name</code>’ table, in name records with
jdaggett@8276 5876 name ID 1. Mulitple names can be stored for different locales, but
jdaggett@6694 5877 Microsoft recommends fonts always include at least a US English version of
jdaggett@6694 5878 the name. On Windows, Microsoft made the decision for backwards
jdaggett@6694 5879 compatibility to limit this family name to a maximum of four faces; for
jdaggett@6694 5880 larger groupings the "preferred family" (name ID 16) or "WWS family" (name
jdaggett@6694 5881 ID 21) can be used. Other platforms such as OSX don't have this
jdaggett@8276 5882 limitation, so the family name is used to define all possible groupings.
jdaggett@6694 5883
jdaggett@6694 5884 <p>Other name table data provides names used to uniquely identify a
jdaggett@6694 5885 specific face within a family. The full font name (name ID 4) and the
jdaggett@8276 5886 Postscript name (name ID 6) describe a single face uniquely. For example,
jdaggett@8276 5887 the bold face of the Gill Sans family has a fullname of "Gill Sans Bold"
jdaggett@8276 5888 and a Postscript name of "GillSans-Bold". There can be multiple localized
jdaggett@8276 5889 versions of the fullname for a given face, but the Postscript name is
jdaggett@1244 5890 always a unique name made from a limited set of ASCII characters.
jdaggett@1244 5891
jdaggett@1244 5892 <p>On various platforms, different names are used to search for a font. For
jdaggett@1244 5893 example, with the Windows GDI CreateIndirectFont API, either a family or
jdaggett@8276 5894 fullname can be used to lookup a face, while on Mac OS X the
jdaggett@8095 5895 CTFontCreateWithName API call is used to lookup a given face using the
jdaggett@8095 5896 fullname and Postscript name. Under Linux, the fontconfig API allows fonts
jdaggett@8095 5897 to be searched using any of these names. In situations where platform
jdaggett@8095 5898 API's automatically substitute other font choices, it may be necessary to
jdaggett@8095 5899 verify a returned font matches a given name.
jdaggett@1244 5900
jdaggett@1244 5901 <p>The weight of a given face can be determined via the usWeightClass field
jdaggett@1244 5902 of the OS/2 table or inferred from the style name (name ID 2). Likewise,
jdaggett@1244 5903 the width can be determined via the usWidthClass of the OS/2 table or
jdaggett@6694 5904 inferred from the style name. For historical reasons related to synthetic
jdaggett@6694 5905 bolding at weights 200 or lower with the Windows GDI API, font designers
jdaggett@6694 5906 have sometimes skewed values in the OS/2 table to avoid these weights.
jdaggett@1244 5907
jdaggett@1244 5908 <p>Rendering complex scripts that use contextual shaping such as Thai,
jdaggett@1244 5909 Arabic and Devanagari requires features present only in OpenType or AAT
jdaggett@1244 5910 fonts. Currently, complex script rendering is supported on Windows and
jdaggett@7521 5911 Linux using OpenType font features while both OpenType and AAT font
jdaggett@7521 5912 features are used under Mac OS X.
jdaggett@1244 5913
jdaggett@2472 5914 <h2 class=no-num id=ch-ch-ch-changes>Changes</h2>
jdaggett@2472 5915
jdaggett@2472 5916 <h3 class=no-num id=recent-changes> Changes from the <a
jdaggett@8699 5917 href="http://www.w3.org/TR/2013/WD-css-fonts-3-20130711/">July 2013 CSS3
jdaggett@8699 5918 Fonts Last Call Working Draft</a></h3>
jdaggett@2472 5919
jdaggett@2472 5920 <p>Major changes include:
jdaggett@2472 5921
jdaggett@2472 5922 <ul>
jdaggett@8804 5923 <li>reorder feature precedence such that features implied by other CSS
jdaggett@8804 5924 properties override ‘<code class=property>font-variant</code>’
jdaggett@8804 5925 settings
jdaggett@8860 5926
jdaggett@8860 5927 <li>switched examples to use .woff files
jdaggett@8860 5928
jdaggett@8872 5929 <li>revised wording of font fetching algorithm
jdaggett@8872 5930
jdaggett@8968 5931 <li>drop ‘<code class=property>auto</code>’ value for ‘<a
jdaggett@8968 5932 href="#propdef-font-size-adjust"><code
jdaggett@8930 5933 class=property>font-size-adjust</code></a>’
jdaggett@8930 5934
jdaggett@8968 5935 <li>clarify effect of ‘<a href="#propdef-font-size-adjust"><code
jdaggett@8968 5936 class=property>font-size-adjust</code></a>’ on <a class=property
jdaggett@8968 5937 href="http://www.w3.org/TR/CSS2/visudet.html#propdef-line-height">‘<code
jdaggett@8968 5938 class=property>line-height</code>’</a>
jdaggett@8968 5939
jdaggett@8930 5940 <li>allow user agents to synthesize OpenType <span class=tag>kern</span>
jdaggett@8930 5941 feature
jdaggett@8930 5942
jdaggett@8860 5943 <li>minor editorial cleanups
jdaggett@2472 5944 </ul>
jdaggett@2472 5945
jdaggett@529 5946 <h2 class=no-num id=acknowledgments>Acknowledgments</h2>
jdaggett@529 5947
jdaggett@1662 5948 <p>I'd like to thank Tal Leming, Jonathan Kew and Christopher Slye for all
jdaggett@1662 5949 their help and feedback. John Hudson was kind enough to take the time to
jdaggett@2472 5950 explain the subtleties of OpenType language tags and provided the example
jdaggett@2472 5951 of character variant usage for displaying text on Byzantine seals. Ken
jdaggett@2472 5952 Lunde and Eric Muller provided valuable feedback on CJK OpenType features
jdaggett@2472 5953 and Unicode variation selectors. The idea for supporting font features by
jdaggett@8313 5954 using <a href="#propdef-font-variant"
jdaggett@8313 5955 title="font-variant!!property">‘<code
jdaggett@8313 5956 class=property>font-variant</code>’</a> subproperties originated with
jdaggett@8313 5957 Håkon Wium Lie, Adam Twardoch and Tal Leming. Elika Etemad supplied some
jdaggett@8313 5958 of the initial design ideas for the <a
jdaggett@8311 5959 href="#at-font-feature-values-rule"><code>@font-feature-values</code></a>
jdaggett@8311 5960 rule. Thanks also to House Industries for allowing the use of Ed Interlock
jdaggett@8311 5961 in the discretionary ligatures example.
jdaggett@1662 5962
jdaggett@529 5963 <p>A special thanks to Robert Bringhurst for the sublime mind expansion
jdaggett@529 5964 that is <em>The Elements of Typographic Style</em>.
jdaggett@529 5965
jdaggett@7242 5966 <h2 class=no-num id=conformance> Conformance</h2>
jdaggett@7242 5967
jdaggett@7242 5968 <h3 class=no-num id=conventions> Document Conventions</h3>
jdaggett@7242 5969
jdaggett@7242 5970 <p>Conformance requirements are expressed with a combination of descriptive
jdaggett@7242 5971 assertions and RFC 2119 terminology. The key words “MUST”, “MUST
jdaggett@7242 5972 NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”,
jdaggett@7242 5973 “SHOULD NOT”, “RECOMMENDED”, “MAY”, and “OPTIONAL” in the
jdaggett@7242 5974 normative parts of this document are to be interpreted as described in RFC
jdaggett@7242 5975 2119. However, for readability, these words do not appear in all uppercase
jdaggett@7242 5976 letters in this specification.
jdaggett@7242 5977
jdaggett@7242 5978 <p>All of the text of this specification is normative except sections
jdaggett@7242 5979 explicitly marked as non-normative, examples, and notes. <a
jdaggett@7242 5980 href="#RFC2119" rel=biblioentry>[RFC2119]<!--{{!RFC2119}}--></a>
jdaggett@7242 5981
jdaggett@7242 5982 <p>Examples in this specification are introduced with the words “for
jdaggett@7242 5983 example” or are set apart from the normative text with
jdaggett@7242 5984 <code>class="example"</code>, like this:
jdaggett@7242 5985
jdaggett@7242 5986 <div class=example>
jdaggett@7242 5987 <p>This is an example of an informative example.
jdaggett@7242 5988 </div>
jdaggett@7242 5989
jdaggett@7242 5990 <p>Informative notes begin with the word “Note” and are set apart from
jdaggett@7242 5991 the normative text with <code>class="note"</code>, like this:
jdaggett@7242 5992
jdaggett@7242 5993 <p class=note>Note, this is an informative note.
jdaggett@7242 5994
jdaggett@7242 5995 <h3 class=no-num id=conformance-classes> Conformance Classes</h3>
jdaggett@7242 5996
jdaggett@7242 5997 <p>Conformance to CSS Fonts Level 3 Module is defined for three conformance
jdaggett@7242 5998 classes:
jdaggett@7242 5999
jdaggett@7242 6000 <dl>
jdaggett@7243 6001 <dt><dfn id=style-sheet title="style sheet!!as conformance class">style
jdaggett@7242 6002 sheet</dfn>
jdaggett@7242 6003
jdaggett@7242 6004 <dd>A <a href="http://www.w3.org/TR/CSS21/conform.html#style-sheet">CSS
jdaggett@7242 6005 style sheet</a>.
jdaggett@7242 6006
jdaggett@7243 6007 <dt><dfn id=renderer>renderer</dfn>
jdaggett@7242 6008
jdaggett@7242 6009 <dd>A <a href="http://www.w3.org/TR/CSS21/conform.html#user-agent">UA</a>
jdaggett@7242 6010 that interprets the semantics of a style sheet and renders documents that
jdaggett@7242 6011 use them.
jdaggett@7242 6012
jdaggett@7242 6013 <dt><dfn id=authoring-tool>authoring tool</dfn>
jdaggett@7242 6014
jdaggett@7242 6015 <dd>A <a href="http://www.w3.org/TR/CSS21/conform.html#user-agent">UA</a>
jdaggett@7242 6016 that writes a style sheet.
jdaggett@7242 6017 </dl>
jdaggett@7242 6018
jdaggett@7242 6019 <p>A style sheet is conformant to CSS Fonts Level 3 Module if all of its
jdaggett@7242 6020 declarations that use properties defined in this module have values that
jdaggett@7242 6021 are valid according to the generic CSS grammar and the individual grammars
jdaggett@7242 6022 of each property as given in this module.
jdaggett@7242 6023
jdaggett@7242 6024 <p>A renderer is conformant to CSS Fonts Level 3 Module if, in addition to
jdaggett@7242 6025 interpreting the style sheet as defined by the appropriate specifications,
jdaggett@7242 6026 it supports all the features defined by CSS Fonts Level 3 Module by
jdaggett@7242 6027 parsing them correctly and rendering the document accordingly. However,
jdaggett@7242 6028 the inability of a UA to correctly render a document due to limitations of
jdaggett@7242 6029 the device does not make the UA non-conformant. (For example, a UA is not
jdaggett@7242 6030 required to render color on a monochrome monitor.)
jdaggett@7242 6031
jdaggett@7242 6032 <p>An authoring tool is conformant to CSS Fonts Level 3 Module if it writes
jdaggett@7242 6033 style sheets that are syntactically correct according to the generic CSS
jdaggett@7242 6034 grammar and the individual grammars of each feature in this module, and
jdaggett@7242 6035 meet all other conformance requirements of style sheets as described in
jdaggett@7242 6036 this module.
jdaggett@7242 6037
jdaggett@7242 6038 <h3 class=no-num id=partial> Partial Implementations</h3>
jdaggett@7242 6039
jdaggett@7242 6040 <p>So that authors can exploit the forward-compatible parsing rules to
jdaggett@7242 6041 assign fallback values, CSS renderers <strong>must</strong> treat as
jdaggett@7242 6042 invalid (and <a
jdaggett@7242 6043 href="http://www.w3.org/TR/CSS21/conform.html#ignore">ignore as
jdaggett@7242 6044 appropriate</a>) any at-rules, properties, property values, keywords, and
jdaggett@7242 6045 other syntactic constructs for which they have no usable level of support.
jdaggett@7242 6046 In particular, user agents <strong>must not</strong> selectively ignore
jdaggett@7242 6047 unsupported component values and honor supported values in a single
jdaggett@7242 6048 multi-value property declaration: if any value is considered invalid (as
jdaggett@7242 6049 unsupported values must be), CSS requires that the entire declaration be
jdaggett@7242 6050 ignored.
jdaggett@7242 6051
jdaggett@7242 6052 <h3 class=no-num id=experimental> Experimental Implementations</h3>
jdaggett@7242 6053
jdaggett@7242 6054 <p>To avoid clashes with future CSS features, the CSS2.1 specification
jdaggett@7242 6055 reserves a <a
jdaggett@7242 6056 href="http://www.w3.org/TR/CSS21/syndata.html#vendor-keywords">prefixed
jdaggett@7242 6057 syntax</a> for proprietary and experimental extensions to CSS.
jdaggett@7242 6058
jdaggett@7242 6059 <p>Prior to a specification reaching the Candidate Recommendation stage in
jdaggett@7242 6060 the W3C process, all implementations of a CSS feature are considered
jdaggett@7242 6061 experimental. The CSS Working Group recommends that implementations use a
jdaggett@7242 6062 vendor-prefixed syntax for such features, including those in W3C Working
jdaggett@7242 6063 Drafts. This avoids incompatibilities with future changes in the draft.
jdaggett@7242 6064
jdaggett@7242 6065 <h3 class=no-num id=testing> Non-Experimental Implementations</h3>
jdaggett@7242 6066
jdaggett@7242 6067 <p>Once a specification reaches the Candidate Recommendation stage,
jdaggett@7242 6068 non-experimental implementations are possible, and implementors should
jdaggett@7242 6069 release an unprefixed implementation of any CR-level feature they can
jdaggett@7242 6070 demonstrate to be correctly implemented according to spec.
jdaggett@7242 6071
jdaggett@7242 6072 <p>To establish and maintain the interoperability of CSS across
jdaggett@7242 6073 implementations, the CSS Working Group requests that non-experimental CSS
jdaggett@7242 6074 renderers submit an implementation report (and, if necessary, the
jdaggett@7242 6075 testcases used for that implementation report) to the W3C before releasing
jdaggett@7242 6076 an unprefixed implementation of any CSS features. Testcases submitted to
jdaggett@7242 6077 W3C are subject to review and correction by the CSS Working Group.
jdaggett@7242 6078
jdaggett@7242 6079 <p>Further information on submitting testcases and implementation reports
jdaggett@7242 6080 can be found from on the CSS Working Group's website at <a
jdaggett@7242 6081 href="http://www.w3.org/Style/CSS/Test/">http://www.w3.org/Style/CSS/Test/</a>.
jdaggett@7242 6082 Questions should be directed to the <a
jdaggett@7242 6083 href="http://lists.w3.org/Archives/Public/public-css-testsuite">public-css-testsuite@w3.org</a>
jdaggett@7242 6084 mailing list.
jdaggett@7242 6085
jdaggett@484 6086 <h2 class=no-num id=references>References</h2>
jdaggett@484 6087
jdaggett@1662 6088 <h3 class=no-num id=normative-references>Normative References</h3>
jdaggett@484 6089 <!--begin-normative-->
jdaggett@484 6090 <!-- Sorted by label -->
jdaggett@484 6091
jdaggett@484 6092 <dl class=bibliography>
jdaggett@8031 6093 <dd style="display: none"><!-- keeps the doc valid if the DL is empty -->
jdaggett@484 6094 <!---->
jdaggett@531 6095
jdaggett@2461 6096 <dt id=CHARMOD>[CHARMOD]
jdaggett@2461 6097
jdaggett@2461 6098 <dd>Martin J. Dürst; et al. <a
jdaggett@2737 6099 href="http://www.w3.org/TR/2005/REC-charmod-20050215/"><cite>Character
jdaggett@2461 6100 Model for the World Wide Web 1.0: Fundamentals.</cite></a> 15 February
jdaggett@2461 6101 2005. W3C Recommendation. URL: <a
jdaggett@2737 6102 href="http://www.w3.org/TR/2005/REC-charmod-20050215/">http://www.w3.org/TR/2005/REC-charmod-20050215/</a>
jdaggett@2461 6103 </dd>
jdaggett@2461 6104 <!---->
jdaggett@2461 6105
jdaggett@2457 6106 <dt id=CORS>[CORS]
jdaggett@1662 6107
jdaggett@1662 6108 <dd>Anne van Kesteren. <a
jdaggett@7242 6109 href="http://www.w3.org/TR/2013/CR-cors-20130129/"><cite>Cross-Origin
jdaggett@7242 6110 Resource Sharing.</cite></a> 29 January 2013. W3C Candidate
jdaggett@7242 6111 Recommendation. (Work in progress.) URL: <a
jdaggett@7242 6112 href="http://www.w3.org/TR/2013/CR-cors-20130129/">http://www.w3.org/TR/2013/CR-cors-20130129/</a>
jdaggett@1662 6113 </dd>
jdaggett@1662 6114 <!---->
jdaggett@1662 6115
jdaggett@3041 6116 <dt id=CSS21>[CSS21]
jdaggett@3041 6117
jdaggett@3041 6118 <dd>Bert Bos; et al. <a
jdaggett@8031 6119 href="http://www.w3.org/TR/2011/REC-CSS2-20110607"><cite>Cascading Style
jdaggett@3041 6120 Sheets Level 2 Revision 1 (CSS 2.1) Specification.</cite></a> 7 June
jdaggett@3041 6121 2011. W3C Recommendation. URL: <a
jdaggett@8031 6122 href="http://www.w3.org/TR/2011/REC-CSS2-20110607">http://www.w3.org/TR/2011/REC-CSS2-20110607</a>
jdaggett@3041 6123 </dd>
jdaggett@3041 6124 <!---->
jdaggett@3041 6125
jdaggett@5833 6126 <dt id=CSS3VAL>[CSS3VAL]
jdaggett@5833 6127
jdaggett@5833 6128 <dd>Håkon Wium Lie; Tab Atkins; Elika J. Etemad. <a
jdaggett@8957 6129 href="http://www.w3.org/TR/2013/CR-css3-values-20130730/"><cite>CSS
jdaggett@8957 6130 Values and Units Module Level 3.</cite></a> 30 July 2013. W3C Candidate
jdaggett@6701 6131 Recommendation. (Work in progress.) URL: <a
jdaggett@8957 6132 href="http://www.w3.org/TR/2013/CR-css3-values-20130730/">http://www.w3.org/TR/2013/CR-css3-values-20130730/</a>
jdaggett@5833 6133 </dd>
jdaggett@5833 6134 <!---->
jdaggett@5833 6135
jdaggett@1662 6136 <dt id=HTML5>[HTML5]
jdaggett@1662 6137
jdaggett@8957 6138 <dd>Robin Berjon; et al. <a
jdaggett@8957 6139 href="http://www.w3.org/TR/2013/CR-html5-20130806/"><cite>HTML5.</cite></a>
jdaggett@8957 6140 6 August 2013. W3C Candidate Recommendation. (Work in progress.) URL: <a
jdaggett@8957 6141 href="http://www.w3.org/TR/2013/CR-html5-20130806/">http://www.w3.org/TR/2013/CR-html5-20130806/</a>
jdaggett@1662 6142 </dd>
jdaggett@1662 6143 <!---->
jdaggett@1662 6144
jdaggett@1662 6145 <dt id=OPEN-FONT-FORMAT>[OPEN-FONT-FORMAT]
jdaggett@1662 6146
jdaggett@1662 6147 <dd><a
bert@8683 6148 href="http://www.iso.org/iso/home/store/catalogue_ics/catalogue_detail_ics.htm?csnumber=52136"><cite>Information
jdaggett@1662 6149 technology — Coding of audio-visual objects — Part 22: Open Font
jdaggett@1662 6150 Format.</cite></a> International Organization for Standardization.
jdaggett@1662 6151 ISO/IEC 14496-22:2009. URL: <a
bert@8683 6152 href="http://www.iso.org/iso/home/store/catalogue_ics/catalogue_detail_ics.htm?csnumber=52136">http://www.iso.org/iso/home/store/catalogue_ics/catalogue_detail_ics.htm?csnumber=52136</a>
jdaggett@1662 6153 </dd>
jdaggett@1662 6154 <!---->
jdaggett@1662 6155
jdaggett@1662 6156 <dt id=OPENTYPE>[OPENTYPE]
jdaggett@1662 6157
jdaggett@1662 6158 <dd><a
jdaggett@1662 6159 href="http://www.microsoft.com/typography/otspec/default.htm"><cite>OpenType
jdaggett@1662 6160 specification.</cite></a> Microsoft. URL: <a
jdaggett@1662 6161 href="http://www.microsoft.com/typography/otspec/default.htm">http://www.microsoft.com/typography/otspec/default.htm</a>
jdaggett@1662 6162 </dd>
jdaggett@1662 6163 <!---->
jdaggett@1662 6164
jdaggett@1662 6165 <dt id=OPENTYPE-FEATURES>[OPENTYPE-FEATURES]
jdaggett@1662 6166
jdaggett@1662 6167 <dd><a
jdaggett@1662 6168 href="http://www.microsoft.com/typography/otspec/featurelist.htm"><cite>OpenType
jdaggett@1662 6169 feature registry.</cite></a> Microsoft. URL: <a
jdaggett@1662 6170 href="http://www.microsoft.com/typography/otspec/featurelist.htm">http://www.microsoft.com/typography/otspec/featurelist.htm</a>
jdaggett@1662 6171 </dd>
jdaggett@1662 6172 <!---->
jdaggett@1662 6173
jdaggett@7103 6174 <dt id=RFC2119>[RFC2119]
jdaggett@7103 6175
jdaggett@7103 6176 <dd>S. Bradner. <a href="http://www.ietf.org/rfc/rfc2119.txt"><cite>Key
jdaggett@7103 6177 words for use in RFCs to Indicate Requirement Levels.</cite></a> Internet
jdaggett@7103 6178 RFC 2119. URL: <a
jdaggett@7103 6179 href="http://www.ietf.org/rfc/rfc2119.txt">http://www.ietf.org/rfc/rfc2119.txt</a>
jdaggett@7103 6180 </dd>
jdaggett@7103 6181 <!---->
jdaggett@7103 6182
jdaggett@2457 6183 <dt id=UAX15>[UAX15]
jdaggett@2457 6184
jdaggett@7242 6185 <dd>Mark Davis; Ken Whistler. <a
jdaggett@7242 6186 href="http://www.unicode.org/reports/tr15/"><cite>Unicode Normalization
jdaggett@7242 6187 Forms.</cite></a> 31 August 2012. Unicode Standard Annex #15. URL: <a
jdaggett@7242 6188 href="http://www.unicode.org/reports/tr15/">http://www.unicode.org/reports/tr15/</a>
jdaggett@2457 6189 </dd>
jdaggett@2457 6190 <!---->
jdaggett@2457 6191
jdaggett@1856 6192 <dt id=UAX29>[UAX29]
jdaggett@1856 6193
jdaggett@1856 6194 <dd>Mark Davis. <a
jdaggett@5809 6195 href="http://www.unicode.org/reports/tr29/"><cite>Unicode Text
jdaggett@7242 6196 Segmentation.</cite></a> 12 September 2012. Unicode Standard Annex #29.
jdaggett@2461 6197 URL: <a
jdaggett@5809 6198 href="http://www.unicode.org/reports/tr29/">http://www.unicode.org/reports/tr29/</a>
jdaggett@1856 6199 </dd>
jdaggett@1856 6200 <!---->
jdaggett@1856 6201
jdaggett@3041 6202 <dt id=UNICODE6>[UNICODE6]
jdaggett@531 6203
jdaggett@531 6204 <dd>The Unicode Consortium. <a
jdaggett@7242 6205 href="http://www.unicode.org/versions/Unicode6.2.0/"><cite>The Unicode
jdaggett@7242 6206 Standard, Version 6.2.0.</cite></a> Defined by: The Unicode Standard,
jdaggett@7242 6207 Version 6.2.0 URL: <a
jdaggett@7242 6208 href="http://www.unicode.org/versions/Unicode6.2.0/">http://www.unicode.org/versions/Unicode6.2.0/</a>
jdaggett@531 6209 </dd>
jdaggett@531 6210 <!---->
jdaggett@484 6211 </dl>
jdaggett@484 6212 <!--end-normative-->
jdaggett@3041 6213 <!--{{!CSS21}}-->
jdaggett@5833 6214 <!--{{!CSS3VAL}}-->
jdaggett@1662 6215 <!--{{!OPENTYPE}}-->
jdaggett@1662 6216 <!--{{!OPENTYPE-FEATURES}}-->
jdaggett@1662 6217 <!--{{!OPEN-FONT-FORMAT}}-->
jdaggett@3041 6218 <!--{{!UNICODE6}}-->
jdaggett@2457 6219 <!--{{!UAX15}}-->
jdaggett@1856 6220 <!--{{!UAX29}}-->
jdaggett@2457 6221 <!--{{!CORS}}-->
jdaggett@1662 6222 <!--{{!HTML5}}-->
jdaggett@2461 6223 <!--{{!CHARMOD}}-->
jdaggett@1662 6224
jdaggett@1662 6225 <h3 class=no-num id=other-references>Other References</h3>
jdaggett@484 6226 <!--begin-informative-->
jdaggett@484 6227 <!-- Sorted by label -->
jdaggett@484 6228
jdaggett@484 6229 <dl class=bibliography>
jdaggett@8031 6230 <dd style="display: none"><!-- keeps the doc valid if the DL is empty -->
jdaggett@484 6231 <!---->
jdaggett@484 6232
jdaggett@3042 6233 <dt id=AAT-FEATURES>[AAT-FEATURES]
jdaggett@3042 6234
jdaggett@3042 6235 <dd><a href="http://developer.apple.com/fonts/registry/"><cite>Apple
jdaggett@3042 6236 Advanced Typography font feature registry.</cite></a> Apple. URL: <a
jdaggett@3042 6237 href="http://developer.apple.com/fonts/registry/">http://developer.apple.com/fonts/registry/</a>
jdaggett@3042 6238 </dd>
jdaggett@3042 6239 <!---->
jdaggett@3042 6240
jdaggett@512 6241 <dt id=ARABIC-TYPO>[ARABIC-TYPO]
jdaggett@512 6242
jdaggett@513 6243 <dd>Huda Smitshuijzen AbiFares. <cite>Arabic Typography: A Comprehensive
jdaggett@1148 6244 Sourcebook.</cite> Saqi Books. 2001. ISBN 0-86356-347-3.</dd>
jdaggett@512 6245 <!---->
jdaggett@512 6246
jdaggett@3042 6247 <dt id=CHARMOD-NORM>[CHARMOD-NORM]
jdaggett@3042 6248
jdaggett@3042 6249 <dd>François Yergeau; et al. <a
jdaggett@5809 6250 href="http://www.w3.org/TR/2012/WD-charmod-norm-20120501/"><cite>Character
jdaggett@5809 6251 Model for the World Wide Web 1.0: Normalization.</cite></a> 1 May 2012.
jdaggett@5809 6252 W3C Working Draft. (Work in progress.) URL: <a
jdaggett@5809 6253 href="http://www.w3.org/TR/2012/WD-charmod-norm-20120501/">http://www.w3.org/TR/2012/WD-charmod-norm-20120501/</a>
jdaggett@3042 6254 </dd>
jdaggett@3042 6255 <!---->
jdaggett@3042 6256
jdaggett@1732 6257 <dt id=CJKV-INFO-PROCESSING>[CJKV-INFO-PROCESSING]
jdaggett@1732 6258
jdaggett@1732 6259 <dd>Ken Lunde. <cite>CJKV Information Processing, Second Edition.</cite>
jdaggett@1732 6260 O'Reilly Media, Inc. 2009. ISBN 0-596-51447-1.</dd>
jdaggett@1732 6261 <!---->
jdaggett@1732 6262
jdaggett@3460 6263 <dt id=CSS3-CONDITIONAL>[CSS3-CONDITIONAL]
jdaggett@3460 6264
jdaggett@3460 6265 <dd>L. David Baron. <a
jdaggett@8386 6266 href="http://www.w3.org/TR/2013/CR-css3-conditional-20130404/"><cite>CSS
jdaggett@8386 6267 Conditional Rules Module Level 3.</cite></a> 4 April 2013. W3C Candidate
jdaggett@8386 6268 Recommendation. (Work in progress.) URL: <a
jdaggett@8386 6269 href="http://www.w3.org/TR/2013/CR-css3-conditional-20130404/">http://www.w3.org/TR/2013/CR-css3-conditional-20130404/</a>
jdaggett@3460 6270 </dd>
jdaggett@3460 6271 <!---->
jdaggett@3460 6272
jdaggett@6701 6273 <dt id=CSS3TEXT>[CSS3TEXT]
jdaggett@6701 6274
jdaggett@6701 6275 <dd>Elika J. Etemad; Koji Ishii. <a
jdaggett@7041 6276 href="http://www.w3.org/TR/2012/WD-css3-text-20121113/"><cite>CSS Text
jdaggett@7041 6277 Module Level 3.</cite></a> 13 November 2012. W3C Working Draft. (Work in
jdaggett@6701 6278 progress.) URL: <a
jdaggett@7041 6279 href="http://www.w3.org/TR/2012/WD-css3-text-20121113/">http://www.w3.org/TR/2012/WD-css3-text-20121113/</a>
jdaggett@6701 6280 </dd>
jdaggett@6701 6281 <!---->
jdaggett@6701 6282
jdaggett@1856 6283 <dt id=DIGITAL-TYPOGRAPHY>[DIGITAL-TYPOGRAPHY]
jdaggett@1856 6284
jdaggett@1856 6285 <dd>Richard Rubinstein. <cite>Digital Typography, An Introduction to Type
jdaggett@1856 6286 and Composition for Computer System Design.</cite> Addison-Wesley. 1988.
jdaggett@1856 6287 ISBN 0-201-17633-5.</dd>
jdaggett@1856 6288 <!---->
jdaggett@1856 6289
jdaggett@7022 6290 <dt id=DOM-LEVEL-2-STYLE>[DOM-LEVEL-2-STYLE]
jdaggett@7022 6291
jdaggett@7022 6292 <dd>Chris Wilson; Philippe Le Hégaret; Vidur Apparao. <a
jdaggett@7179 6293 href="http://www.w3.org/TR/2000/REC-DOM-Level-2-Style-20001113/"><cite>Document
jdaggett@7022 6294 Object Model (DOM) Level 2 Style Specification.</cite></a> 13 November
jdaggett@7022 6295 2000. W3C Recommendation. URL: <a
jdaggett@7179 6296 href="http://www.w3.org/TR/2000/REC-DOM-Level-2-Style-20001113/">http://www.w3.org/TR/2000/REC-DOM-Level-2-Style-20001113/</a>
jdaggett@7022 6297 </dd>
jdaggett@7022 6298 <!---->
jdaggett@7022 6299
jdaggett@498 6300 <dt id=ELEMTYPO>[ELEMTYPO]
jdaggett@498 6301
jdaggett@498 6302 <dd>Robert Bringhurst. <cite>The Elements of Typographic Style, Version
jdaggett@7488 6303 4.</cite> Hartley &amp; Marks. 2013. ISBN 0-88179-212-8.</dd>
jdaggett@498 6304 <!---->
jdaggett@498 6305
jdaggett@513 6306 <dt id=LANGCULTTYPE>[LANGCULTTYPE]
jdaggett@513 6307
jdaggett@1148 6308 <dd>John D. Berry, Ed. <cite>Language Culture Type.</cite> Graphis. 2001.
jdaggett@1148 6309 ISBN 1-932026-01-0.</dd>
jdaggett@512 6310 <!---->
jdaggett@1662 6311
jdaggett@1662 6312 <dt id=OPENTYPE-FONT-GUIDE>[OPENTYPE-FONT-GUIDE]
jdaggett@1662 6313
jdaggett@1662 6314 <dd><a
jdaggett@3538 6315 href="https://www.fontfont.com/staticcontent/downloads/FF_OT_User_Guide.pdf"><cite>OpenType
jdaggett@1662 6316 User Guide.</cite></a> FontShop International. URL: <a
jdaggett@3538 6317 href="https://www.fontfont.com/staticcontent/downloads/FF_OT_User_Guide.pdf">https://www.fontfont.com/staticcontent/downloads/FF_OT_User_Guide.pdf</a>
jdaggett@1662 6318 </dd>
jdaggett@1662 6319 <!---->
jdaggett@1856 6320
jdaggett@2527 6321 <dt id=RASTER-TRAGEDY>[RASTER-TRAGEDY]
jdaggett@2527 6322
jdaggett@2527 6323 <dd>Beat Stamm. <a href="http://www.rastertragedy.com/"><cite>The Raster
jdaggett@6659 6324 Tragedy at Low-Resolution Revisited.</cite></a> 7 December 2011. URL: <a
jdaggett@2527 6325 href="http://www.rastertragedy.com/">http://www.rastertragedy.com/</a></dd>
jdaggett@2527 6326 <!---->
jdaggett@2527 6327
jdaggett@1856 6328 <dt id=WINDOWS-GLYPH-PROC>[WINDOWS-GLYPH-PROC]
jdaggett@1856 6329
jdaggett@1856 6330 <dd>John Hudson. <a
jdaggett@1856 6331 href="http://www.microsoft.com/typography/developers/opentype/default.htm"><cite>Windows
jdaggett@1856 6332 Glyph Processing.</cite></a> Microsoft Typogrraphy. URL: <a
jdaggett@1856 6333 href="http://www.microsoft.com/typography/developers/opentype/default.htm">http://www.microsoft.com/typography/developers/opentype/default.htm</a>
jdaggett@1856 6334 </dd>
jdaggett@1856 6335 <!---->
jdaggett@484 6336 </dl>
jdaggett@484 6337 <!--end-informative-->
jdaggett@518 6338 <!--{{ARABIC-TYPO}}-->
jdaggett@1732 6339 <!--{{CJKV-INFO-PROCESSING}}-->
jdaggett@1856 6340 <!--{{DIGITAL-TYPOGRAPHY}}-->
jdaggett@7022 6341 <!--{{DOM-LEVEL-2-STYLE}}-->
jdaggett@518 6342 <!--{{ELEMTYPO}}-->
jdaggett@1856 6343 <!--{{LANGCULTTYPE}}-->
jdaggett@1662 6344 <!--{{OPENTYPE-FONT-GUIDE}}-->
jdaggett@2527 6345 <!--{{RASTER-TRAGEDY}}-->
jdaggett@1856 6346 <!--{{WINDOWS-GLYPH-PROC}}-->
jdaggett@3042 6347 <!--{{CHARMOD-NORM}}-->
jdaggett@3042 6348 <!--{{AAT-FEATURES}}-->
jdaggett@3460 6349 <!--{{CSS3-CONDITIONAL}}-->
jdaggett@6701 6350 <!--{{CSS3TEXT}}-->
jdaggett@484 6351
jdaggett@484 6352 <h2 class=no-num id=index>Index</h2>
jdaggett@484 6353 <!--begin-index-->
jdaggett@484 6354
jdaggett@484 6355 <ul class=indexlist>
jdaggett@8278 6356 <li>100...900 weight values, <a href="#font-weight-numeric-values"
jdaggett@8278 6357 title="100...900 weight values"><strong>3.2</strong></a>
jdaggett@8278 6358
jdaggett@8225 6359 <li><var>&lt;absolute-size&gt;</var>, <a href="#absolute-size-value"
jdaggett@7060 6360 title="&lt;absolute-size&gt;"><strong>3.5</strong></a>
jdaggett@890 6361
jdaggett@8225 6362 <li><var>&lt;common-lig-values&gt;</var>, <a href="#common-lig-values"
jdaggett@8225 6363 title="&lt;common-lig-values&gt;"><strong>6.4</strong></a>
jdaggett@2479 6364
jdaggett@2479 6365 <li><var>&lt;contextual-alt-values&gt;</var>, <a
jdaggett@8225 6366 href="#contextual-alt-values"
jdaggett@6176 6367 title="&lt;contextual-alt-values&gt;"><strong>6.4</strong></a>
jdaggett@2479 6368
jdaggett@8225 6369 <li><var>&lt;discretionary-lig-values&gt;</var>, <a
jdaggett@8225 6370 href="#discretionary-lig-values"
jdaggett@8225 6371 title="&lt;discretionary-lig-values&gt;"><strong>6.4</strong></a>
jdaggett@3460 6372
jdaggett@2479 6373 <li><var>&lt;east-asian-variant-values&gt;</var>, <a
jdaggett@8225 6374 href="#east-asian-variant-values"
jdaggett@2479 6375 title="&lt;east-asian-variant-values&gt;"><strong>6.10</strong></a>
jdaggett@2479 6376
jdaggett@2479 6377 <li><var>&lt;east-asian-width-values&gt;</var>, <a
jdaggett@8225 6378 href="#east-asian-width-values"
jdaggett@2479 6379 title="&lt;east-asian-width-values&gt;"><strong>6.10</strong></a>
jdaggett@2479 6380
jdaggett@8225 6381 <li><var>&lt;family-name&gt;</var>, <a href="#family-name-value"
jdaggett@8225 6382 title="&lt;family-name&gt;"><strong>3.1</strong></a>
jdaggett@8225 6383
jdaggett@8225 6384 <li><var>&lt;feature-tag-value&gt;</var>, <a href="#feature-tag-value"
jdaggett@2515 6385 title="&lt;feature-tag-value&gt;"><strong>6.12</strong></a>
jdaggett@2515 6386
jdaggett@8225 6387 <li><var>&lt;font-face-name&gt;</var>, <a href="#font-face-name-value"
jdaggett@7060 6388 title="&lt;font-face-name&gt;"><strong>4.3</strong></a>
jdaggett@4624 6389
jdaggett@4624 6390 <li><var>&lt;font-variant-css21&gt;</var>, <a
jdaggett@8225 6391 href="#font-variant-css21-values"
jdaggett@4624 6392 title="&lt;font-variant-css21&gt;"><strong>3.7</strong></a>
jdaggett@4624 6393
jdaggett@8225 6394 <li><var>&lt;generic-family&gt;</var>, <a href="#generic-family-value"
jdaggett@8225 6395 title="&lt;generic-family&gt;"><strong>3.1</strong></a>
jdaggett@8225 6396
jdaggett@8225 6397 <li><var>&lt;historical-lig-values&gt;</var>, <a
jdaggett@8225 6398 href="#historical-lig-values"
jdaggett@8225 6399 title="&lt;historical-lig-values&gt;"><strong>6.4</strong></a>
jdaggett@8225 6400
jdaggett@8225 6401 <li><var>&lt;length&gt;</var>, <a href="#length-size-value"
jdaggett@8225 6402 title="&lt;length&gt;"><strong>3.5</strong></a>
jdaggett@8225 6403
jdaggett@8225 6404 <li><var>&lt;number&gt;</var>, <a href="#aspect-ratio-value"
jdaggett@8225 6405 title="&lt;number&gt;"><strong>3.6</strong></a>
jdaggett@4624 6406
jdaggett@4624 6407 <li><var>&lt;numeric-figure-values&gt;</var>, <a
jdaggett@8225 6408 href="#numeric-figure-values"
jdaggett@4624 6409 title="&lt;numeric-figure-values&gt;"><strong>6.7</strong></a>
jdaggett@4624 6410
jdaggett@4624 6411 <li><var>&lt;numeric-fraction-values&gt;</var>, <a
jdaggett@8225 6412 href="#numeric-fraction-values"
jdaggett@4624 6413 title="&lt;numeric-fraction-values&gt;"><strong>6.7</strong></a>
jdaggett@4624 6414
jdaggett@4624 6415 <li><var>&lt;numeric-spacing-values&gt;</var>, <a
jdaggett@8225 6416 href="#numeric-spacing-values"
jdaggett@4624 6417 title="&lt;numeric-spacing-values&gt;"><strong>6.7</strong></a>
jdaggett@4624 6418
jdaggett@8225 6419 <li><var>&lt;percentage&gt;</var>, <a href="#percentage-size-value"
jdaggett@8225 6420 title="&lt;percentage&gt;"><strong>3.5</strong></a>
jdaggett@8225 6421
jdaggett@8225 6422 <li><var>&lt;relative-size&gt;</var>, <a href="#relative-size-value"
jdaggett@7060 6423 title="&lt;relative-size&gt;"><strong>3.5</strong></a>
jdaggett@7060 6424
jdaggett@8278 6425 <li><var>&lt;string&gt;</var>, <a
jdaggett@8278 6426 href="#font-language-override-string-value"
jdaggett@8278 6427 title="&lt;string&gt;"><strong>6.13</strong></a>
jdaggett@8278 6428
jdaggett@8225 6429 <li><var>&lt;urange&gt;</var>, <a href="#urange-value"
jdaggett@8225 6430 title="&lt;urange&gt;"><strong>4.5</strong></a>
jdaggett@2479 6431
jdaggett@8311 6432 <li><code>@font-face</code>, <a href="#at-font-face-rule"
jdaggett@8311 6433 title="@font-face"><strong>4.1</strong></a>
jdaggett@8311 6434
jdaggett@8311 6435 <li><code>@font-feature-values</code>, <a
jdaggett@8311 6436 href="#at-font-feature-values-rule"
jdaggett@8311 6437 title="@font-feature-values"><strong>6.9</strong></a>
jdaggett@2479 6438
jdaggett@4624 6439 <li>all-petite-caps, <a href="#all-petite-caps"
jdaggett@4624 6440 title=all-petite-caps><strong>6.6</strong></a>
jdaggett@4624 6441
jdaggett@4624 6442 <li>all-small-caps, <a href="#all-small-caps"
jdaggett@4624 6443 title=all-small-caps><strong>6.6</strong></a>
jdaggett@4624 6444
jdaggett@8225 6445 <li>annotation, <a href="#annotation"
jdaggett@7060 6446 title=annotation><strong>6.8</strong></a>
jdaggett@4624 6447
jdaggett@4624 6448 <li>aspect value, <a href="#aspect-value0" title="aspect
jdaggett@4624 6449 value"><strong>3.6</strong></a>
jdaggett@4624 6450
jdaggett@7103 6451 <li>authoring tool, <a href="#authoring-tool" title="authoring
jdaggett@7243 6452 tool"><strong>#</strong></a>
jdaggett@7103 6453
jdaggett@8278 6454 <li>auto
jdaggett@8278 6455 <ul>
jdaggett@8278 6456 <li>font-kerning, <a href="#font-kerning-auto-value" title="auto,
jdaggett@8278 6457 font-kerning"><strong>6.3</strong></a>
jdaggett@8278 6458 </ul>
jdaggett@8278 6459
jdaggett@8278 6460 <li>bold, <a href="#bold" title=bold><strong>3.2</strong></a>
jdaggett@8278 6461
jdaggett@8278 6462 <li>bolder, <a href="#bolder" title=bolder><strong>3.2</strong></a>
jdaggett@8278 6463
jdaggett@7311 6464 <li>character map, <a href="#character-map" title="character
jdaggett@7311 6465 map"><strong>5.2</strong></a>
jdaggett@7311 6466
jdaggett@8225 6467 <li>character-variant, <a href="#character-variant"
jdaggett@7060 6468 title=character-variant><strong>6.8</strong></a>
jdaggett@4624 6469
jdaggett@4624 6470 <li>common-ligatures, <a href="#common-ligatures"
jdaggett@6176 6471 title=common-ligatures><strong>6.4</strong></a>
jdaggett@4624 6472
jdaggett@8391 6473 <li>composite face, <a href="#composite-face" title="composite
jdaggett@8391 6474 face"><strong>5.2</strong></a>
jdaggett@8391 6475
jdaggett@8278 6476 <li>condensed, <a href="#condensed"
jdaggett@8278 6477 title=condensed><strong>3.3</strong></a>
jdaggett@8278 6478
jdaggett@4624 6479 <li>contextual, <a href="#contextual"
jdaggett@6176 6480 title=contextual><strong>6.4</strong></a>
jdaggett@4624 6481
jdaggett@7021 6482 <li>CSSFontFaceRule, <a href="#cssfontfacerule"
jdaggett@7021 6483 title=CSSFontFaceRule><strong>8.1</strong></a>
jdaggett@7021 6484
jdaggett@7021 6485 <li>CSSFontFeatureValuesRule, <a href="#cssfontfeaturevaluesrule"
jdaggett@7021 6486 title=CSSFontFeatureValuesRule><strong>8.2</strong></a>
jdaggett@7021 6487
jdaggett@4624 6488 <li>cursive, definition of, <a href="#cursive0" title="cursive, definition
jdaggett@4624 6489 of"><strong>#</strong></a>
jdaggett@4624 6490
jdaggett@7232 6491 <li>default face, <a href="#default-face" title="default
jdaggett@7309 6492 face"><strong>5.2</strong></a>
jdaggett@7232 6493
jdaggett@8031 6494 <li>descriptor_declaration, <a href="#descriptordeclaration"
jdaggett@8031 6495 title="descriptor_declaration"><strong>4.1</strong></a>
jdaggett@8031 6496
jdaggett@4624 6497 <li>diagonal-fractions, <a href="#diagonal-fractions"
jdaggett@4624 6498 title=diagonal-fractions><strong>6.7</strong></a>
jdaggett@4624 6499
jdaggett@4624 6500 <li>discretionary-ligatures, <a href="#discretionary-ligatures"
jdaggett@6176 6501 title=discretionary-ligatures><strong>6.4</strong></a>
jdaggett@4624 6502
jdaggett@8391 6503 <li>effective character map, <a href="#effective-character-map"
jdaggett@8391 6504 title="effective character map"><strong>4.5</strong></a>
jdaggett@8391 6505
jdaggett@8278 6506 <li>expanded, <a href="#expanded" title=expanded><strong>3.3</strong></a>
jdaggett@8278 6507
jdaggett@8278 6508 <li>extra-condensed, <a href="#extra-condensed"
jdaggett@8278 6509 title=extra-condensed><strong>3.3</strong></a>
jdaggett@8278 6510
jdaggett@8278 6511 <li>extra-expanded, <a href="#extra-expanded"
jdaggett@8278 6512 title=extra-expanded><strong>3.3</strong></a>
jdaggett@8278 6513
jdaggett@4624 6514 <li>fantasy, definition of, <a href="#fantasy0" title="fantasy, definition
jdaggett@4624 6515 of"><strong>#</strong></a>
jdaggett@4624 6516
jdaggett@8031 6517 <li>feature_type, <a href="#featuretype"
jdaggett@8356 6518 title="feature_type"><strong>6.9.1</strong></a>
jdaggett@8031 6519
jdaggett@8031 6520 <li>feature_value_block, <a href="#featurevalueblock"
jdaggett@8356 6521 title="feature_value_block"><strong>6.9.1</strong></a>
jdaggett@8031 6522
jdaggett@8031 6523 <li>feature_value_definition, <a href="#featurevaluedefinition"
jdaggett@8356 6524 title="feature_value_definition"><strong>6.9.1</strong></a>
jdaggett@7679 6525
jdaggett@8431 6526 <li>first available font, <a href="#first-available-font" title="first
jdaggett@8431 6527 available font"><strong>5.2</strong></a>
jdaggett@8431 6528
jdaggett@4624 6529 <li>font, <a href="#propdef-font" title=font><strong>3.7</strong></a>
jdaggett@2472 6530
jdaggett@8356 6531 <li>font specific, <a href="#font-specific" title="font
jdaggett@8356 6532 specific"><strong>6.8</strong></a>
jdaggett@8356 6533
jdaggett@8278 6534 <li>font-family
jdaggett@8278 6535 <ul>
jdaggett@8278 6536 <li>descriptor, <a href="#descdef-font-family" title="font-family,
jdaggett@8278 6537 descriptor"><strong>4.2</strong></a>
jdaggett@8278 6538
jdaggett@8278 6539 <li>property, <a href="#propdef-font-family" title="font-family,
jdaggett@8278 6540 property"><strong>3.1</strong></a>
jdaggett@8278 6541 </ul>
jdaggett@1662 6542
jdaggett@8279 6543 <li>font-feature-settings
jdaggett@8278 6544 <ul>
jdaggett@8278 6545 <li>descriptor, <a href="#descdef-font-feature-settings"
jdaggett@8278 6546 title="font-feature-settings, descriptor"><strong>4.7</strong></a>
jdaggett@8279 6547
jdaggett@8279 6548 <li>property, <a href="#propdef-font-feature-settings"
jdaggett@8279 6549 title="font-feature-settings, property"><strong>6.12</strong></a>
jdaggett@8278 6550 </ul>
jdaggett@7060 6551
jdaggett@1662 6552 <li>font-kerning, <a href="#propdef-font-kerning"
jdaggett@1856 6553 title=font-kerning><strong>6.3</strong></a>
jdaggett@1662 6554
jdaggett@1732 6555 <li>font-language-override, <a href="#propdef-font-language-override"
jdaggett@2118 6556 title=font-language-override><strong>6.13</strong></a>
jdaggett@1662 6557
jdaggett@1662 6558 <li>font-size, <a href="#propdef-font-size"
jdaggett@1662 6559 title=font-size><strong>3.5</strong></a>
jdaggett@1662 6560
jdaggett@1662 6561 <li>font-size-adjust, <a href="#propdef-font-size-adjust"
jdaggett@1662 6562 title=font-size-adjust><strong>3.6</strong></a>
jdaggett@1662 6563
jdaggett@8278 6564 <li>font-stretch
jdaggett@8278 6565 <ul>
jdaggett@8278 6566 <li>descriptor, <a href="#descdef-font-stretch" title="font-stretch,
jdaggett@8278 6567 descriptor"><strong>4.4</strong></a>
jdaggett@8278 6568
jdaggett@8278 6569 <li>property, <a href="#propdef-font-stretch" title="font-stretch,
jdaggett@8278 6570 property"><strong>3.3</strong></a>
jdaggett@8278 6571 </ul>
jdaggett@8278 6572
jdaggett@8278 6573 <li>font-style
jdaggett@8278 6574 <ul>
jdaggett@8278 6575 <li>descriptor, <a href="#descdef-font-style" title="font-style,
jdaggett@8278 6576 descriptor"><strong>4.4</strong></a>
jdaggett@8278 6577
jdaggett@8278 6578 <li>property, <a href="#propdef-font-style" title="font-style,
jdaggett@8278 6579 property"><strong>3.4</strong></a>
jdaggett@8278 6580 </ul>
jdaggett@7060 6581
jdaggett@2487 6582 <li>font-synthesis, <a href="#propdef-font-synthesis"
jdaggett@2487 6583 title=font-synthesis><strong>3.8</strong></a>
jdaggett@2457 6584
jdaggett@8278 6585 <li>font-variant
jdaggett@8278 6586 <ul>
jdaggett@8278 6587 <li>descriptor, <a href="#descdef-font-variant" title="font-variant,
jdaggett@8278 6588 descriptor"><strong>4.7</strong></a>
jdaggett@8278 6589
jdaggett@8278 6590 <li>property, <a href="#propdef-font-variant" title="font-variant,
jdaggett@8278 6591 property"><strong>6.11</strong></a>
jdaggett@8278 6592 </ul>
jdaggett@1662 6593
jdaggett@1662 6594 <li>font-variant-alternates, <a href="#propdef-font-variant-alternates"
jdaggett@2118 6595 title=font-variant-alternates><strong>6.8</strong></a>
jdaggett@1662 6596
jdaggett@1662 6597 <li>font-variant-caps, <a href="#propdef-font-variant-caps"
jdaggett@2118 6598 title=font-variant-caps><strong>6.6</strong></a>
jdaggett@1732 6599
jdaggett@1662 6600 <li>font-variant-east-asian, <a href="#propdef-font-variant-east-asian"
jdaggett@2118 6601 title=font-variant-east-asian><strong>6.10</strong></a>
jdaggett@1662 6602
jdaggett@1662 6603 <li>font-variant-ligatures, <a href="#propdef-font-variant-ligatures"
jdaggett@6176 6604 title=font-variant-ligatures><strong>6.4</strong></a>
jdaggett@1662 6605
jdaggett@1662 6606 <li>font-variant-numeric, <a href="#propdef-font-variant-numeric"
jdaggett@2118 6607 title=font-variant-numeric><strong>6.7</strong></a>
jdaggett@2118 6608
jdaggett@3460 6609 <li>font-variant-position, <a href="#propdef-font-variant-position"
jdaggett@6176 6610 title=font-variant-position><strong>6.5</strong></a>
jdaggett@3460 6611
jdaggett@8278 6612 <li>font-weight
jdaggett@8278 6613 <ul>
jdaggett@8278 6614 <li>descriptor, <a href="#descdef-font-weight" title="font-weight,
jdaggett@8278 6615 descriptor"><strong>4.4</strong></a>
jdaggett@8278 6616
jdaggett@8278 6617 <li>property, <a href="#propdef-font-weight" title="font-weight,
jdaggett@8278 6618 property"><strong>3.2</strong></a>
jdaggett@8278 6619 </ul>
jdaggett@1662 6620
jdaggett@8031 6621 <li>font_face_rule, <a href="#fontfacerule"
jdaggett@8031 6622 title="font_face_rule"><strong>4.1</strong></a>
jdaggett@8031 6623
jdaggett@8225 6624 <li>FONT_FACE_SYM, <a href="#fontfacesym"
jdaggett@8225 6625 title="FONT_FACE_SYM"><strong>4.1</strong></a>
jdaggett@8225 6626
jdaggett@8031 6627 <li>font_family_name, <a href="#fontfamilyname"
jdaggett@8356 6628 title="font_family_name"><strong>6.9.1</strong></a>
jdaggett@8031 6629
jdaggett@8031 6630 <li>font_family_name_list, <a href="#fontfamilynamelist"
jdaggett@8356 6631 title="font_family_name_list"><strong>6.9.1</strong></a>
jdaggett@8031 6632
jdaggett@8031 6633 <li>font_feature_values_rule, <a href="#fontfeaturevaluesrule"
jdaggett@8356 6634 title="font_feature_values_rule"><strong>6.9.1</strong></a>
jdaggett@8031 6635
jdaggett@8225 6636 <li>FONT_FEATURE_VALUES_SYM, <a href="#fontfeaturevaluessym"
jdaggett@8356 6637 title="FONT_FEATURE_VALUES_SYM"><strong>6.9.1</strong></a>
jdaggett@8225 6638
jdaggett@1662 6639 <li>full-width, <a href="#full-width"
jdaggett@2118 6640 title=full-width><strong>6.10</strong></a>
jdaggett@1662 6641
jdaggett@1662 6642 <li>historical-forms, <a href="#historical-forms"
jdaggett@2118 6643 title=historical-forms><strong>6.8</strong></a>
jdaggett@1662 6644
jdaggett@1662 6645 <li>historical-ligatures, <a href="#historical-ligatures"
jdaggett@6176 6646 title=historical-ligatures><strong>6.4</strong></a>
jdaggett@1732 6647
jdaggett@8278 6648 <li>italic, <a href="#italic" title=italic><strong>3.4</strong></a>
jdaggett@8278 6649
jdaggett@2118 6650 <li>jis04, <a href="#jis04" title=jis04><strong>6.10</strong></a>
jdaggett@2118 6651
jdaggett@2118 6652 <li>jis78, <a href="#jis78" title=jis78><strong>6.10</strong></a>
jdaggett@2118 6653
jdaggett@2118 6654 <li>jis83, <a href="#jis83" title=jis83><strong>6.10</strong></a>
jdaggett@2118 6655
jdaggett@2118 6656 <li>jis90, <a href="#jis90" title=jis90><strong>6.10</strong></a>
jdaggett@1662 6657
jdaggett@8278 6658 <li>lighter, <a href="#lighter" title=lighter><strong>3.2</strong></a>
jdaggett@8278 6659
jdaggett@1662 6660 <li>lining-nums, <a href="#lining-nums"
jdaggett@2118 6661 title=lining-nums><strong>6.7</strong></a>
jdaggett@890 6662
jdaggett@890 6663 <li>monospace, definition of, <a href="#monospace0" title="monospace,
jdaggett@890 6664 definition of"><strong>#</strong></a>
jdaggett@890 6665
jdaggett@1662 6666 <li>no-common-ligatures, <a href="#no-common-ligatures"
jdaggett@6176 6667 title=no-common-ligatures><strong>6.4</strong></a>
jdaggett@1662 6668
jdaggett@1662 6669 <li>no-contextual, <a href="#no-contextual"
jdaggett@6176 6670 title=no-contextual><strong>6.4</strong></a>
jdaggett@1662 6671
jdaggett@3460 6672 <li>no-discretionary-ligatures, <a href="#no-discretionary-ligatures"
jdaggett@6176 6673 title=no-discretionary-ligatures><strong>6.4</strong></a>
jdaggett@3460 6674
jdaggett@1662 6675 <li>no-historical-ligatures, <a href="#no-historical-ligatures"
jdaggett@6176 6676 title=no-historical-ligatures><strong>6.4</strong></a>
jdaggett@1662 6677
jdaggett@8278 6678 <li>none
jdaggett@8278 6679 <ul>
jdaggett@8278 6680 <li>font-kerning, <a href="#font-kerning-none-value" title="none,
jdaggett@8278 6681 font-kerning"><strong>6.3</strong></a>
jdaggett@8278 6682
jdaggett@8278 6683 <li>font-size-adjust, <a href="#font-size-adjust-none-value"
jdaggett@8278 6684 title="none, font-size-adjust"><strong>3.6</strong></a>
jdaggett@8278 6685
jdaggett@8278 6686 <li>font-variant, <a href="#font-variant-none-value" title="none,
jdaggett@8278 6687 font-variant"><strong>6.11</strong></a>
jdaggett@8278 6688
jdaggett@8278 6689 <li>font-variant-ligatures, <a href="#font-variant-ligatures-none-value"
jdaggett@8278 6690 title="none, font-variant-ligatures"><strong>6.4</strong></a>
jdaggett@8278 6691 </ul>
jdaggett@8278 6692
jdaggett@8368 6693 <li>normal
jdaggett@8278 6694 <ul>
jdaggett@8278 6695 <li>font-feature-settings, <a href="#font-feature-settings-normal-value"
jdaggett@8278 6696 title="normal, font-feature-settings"><strong>6.12</strong></a>
jdaggett@8278 6697
jdaggett@8278 6698 <li>font-kerning, <a href="#font-kerning-normal-value" title="normal,
jdaggett@8278 6699 font-kerning"><strong>6.3</strong></a>
jdaggett@8278 6700
jdaggett@8278 6701 <li>font-language-override, <a
jdaggett@8278 6702 href="#font-language-override-normal-value" title="normal,
jdaggett@8278 6703 font-language-override"><strong>6.13</strong></a>
jdaggett@8278 6704
jdaggett@8278 6705 <li>font-stretch, <a href="#font-stretch-normal-value" title="normal,
jdaggett@8278 6706 font-stretch"><strong>3.3</strong></a>
jdaggett@8278 6707
jdaggett@8278 6708 <li>font-style, <a href="#font-style-normal-value" title="normal,
jdaggett@8278 6709 font-style"><strong>3.4</strong></a>
jdaggett@8278 6710
jdaggett@8278 6711 <li>font-variant, <a href="#font-variant-normal-value" title="normal,
jdaggett@8278 6712 font-variant"><strong>6.11</strong></a>
jdaggett@8278 6713
jdaggett@8278 6714 <li>font-variant-alternates, <a
jdaggett@8278 6715 href="#font-variant-alternates-normal-value" title="normal,
jdaggett@8278 6716 font-variant-alternates"><strong>6.8</strong></a>
jdaggett@8278 6717
jdaggett@8278 6718 <li>font-variant-caps, <a href="#font-variant-caps-normal-value"
jdaggett@8278 6719 title="normal, font-variant-caps"><strong>6.6</strong></a>
jdaggett@8278 6720
jdaggett@8278 6721 <li>font-variant-east-asian, <a
jdaggett@8278 6722 href="#font-variant-east-asian-normal-value" title="normal,
jdaggett@8278 6723 font-variant-east-asian"><strong>6.10</strong></a>
jdaggett@8278 6724
jdaggett@8278 6725 <li>font-variant-ligatures, <a
jdaggett@8278 6726 href="#font-variant-ligatures-normal-value" title="normal,
jdaggett@8278 6727 font-variant-ligatures"><strong>6.4</strong></a>
jdaggett@8278 6728
jdaggett@8278 6729 <li>font-variant-numeric, <a href="#font-variant-numeric-normal-value"
jdaggett@8278 6730 title="normal, font-variant-numeric"><strong>6.7</strong></a>
jdaggett@8278 6731
jdaggett@8368 6732 <li>font-variant-position, <a href="#font-variant-position-normal-value"
jdaggett@8368 6733 title="normal, font-variant-position"><strong>6.5</strong></a>
jdaggett@8368 6734
jdaggett@8278 6735 <li>font-weight, <a href="#font-weight-normal-value" title="normal,
jdaggett@8278 6736 font-weight"><strong>3.2</strong></a>
jdaggett@8278 6737 </ul>
jdaggett@8278 6738
jdaggett@8278 6739 <li>oblique, <a href="#oblique" title=oblique><strong>3.4</strong></a>
jdaggett@5809 6740
jdaggett@1662 6741 <li>oldstyle-nums, <a href="#oldstyle-nums"
jdaggett@2118 6742 title=oldstyle-nums><strong>6.7</strong></a>
jdaggett@2118 6743
jdaggett@3638 6744 <li>ordinal, <a href="#ordinal" title=ordinal><strong>6.7</strong></a>
jdaggett@3638 6745
jdaggett@8225 6746 <li>ornaments, <a href="#ornaments"
jdaggett@7060 6747 title=ornaments><strong>6.8</strong></a>
jdaggett@2118 6748
jdaggett@1662 6749 <li>petite-caps, <a href="#petite-caps"
jdaggett@2118 6750 title=petite-caps><strong>6.6</strong></a>
jdaggett@1662 6751
jdaggett@1662 6752 <li>proportional-nums, <a href="#proportional-nums"
jdaggett@2118 6753 title=proportional-nums><strong>6.7</strong></a>
jdaggett@1662 6754
jdaggett@1662 6755 <li>proportional-width, <a href="#proportional-width"
jdaggett@2118 6756 title=proportional-width><strong>6.10</strong></a>
jdaggett@512 6757
jdaggett@7243 6758 <li>renderer, <a href="#renderer" title=renderer><strong>#</strong></a>
jdaggett@7103 6759
jdaggett@3638 6760 <li>ruby, <a href="#ruby" title=ruby><strong>6.10</strong></a>
jdaggett@1662 6761
jdaggett@890 6762 <li>sans-serif, definition of, <a href="#sans-serif0" title="sans-serif,
jdaggett@890 6763 definition of"><strong>#</strong></a>
jdaggett@890 6764
jdaggett@8278 6765 <li>semi-condensed, <a href="#semi-condensed-"
jdaggett@8278 6766 title=semi-condensed><strong>3.3</strong></a>
jdaggett@8278 6767
jdaggett@8278 6768 <li>semi-expanded, <a href="#semi-expanded"
jdaggett@8278 6769 title=semi-expanded><strong>3.3</strong></a>
jdaggett@8278 6770
jdaggett@890 6771 <li>serif, definition of, <a href="#serif0" title="serif, definition
jdaggett@890 6772 of"><strong>#</strong></a>
jdaggett@890 6773
jdaggett@2504 6774 <li>simplified, <a href="#simplified"
jdaggett@2504 6775 title=simplified><strong>6.10</strong></a>
jdaggett@1662 6776
jdaggett@1662 6777 <li>slashed-zero, <a href="#slashed-zero"
jdaggett@2118 6778 title=slashed-zero><strong>6.7</strong></a>
jdaggett@1662 6779
jdaggett@1662 6780 <li>small-caps, <a href="#small-caps"
jdaggett@2118 6781 title=small-caps><strong>6.6</strong></a>
jdaggett@1662 6782
jdaggett@1662 6783 <li>src, <a href="#descdef-src" title=src><strong>4.3</strong></a>
jdaggett@1662 6784
jdaggett@1662 6785 <li>stacked-fractions, <a href="#stacked-fractions"
jdaggett@2118 6786 title=stacked-fractions><strong>6.7</strong></a>
jdaggett@2118 6787
jdaggett@7103 6788 <li>style sheet
jdaggett@7103 6789 <ul>
jdaggett@7103 6790 <li>as conformance class, <a href="#style-sheet" title="style sheet, as
jdaggett@7243 6791 conformance class"><strong>#</strong></a>
jdaggett@7103 6792 </ul>
jdaggett@7103 6793
jdaggett@8225 6794 <li>styleset, <a href="#styleset" title=styleset><strong>6.8</strong></a>
jdaggett@8225 6795
jdaggett@8225 6796 <li>stylistic, <a href="#stylistic"
jdaggett@7060 6797 title=stylistic><strong>6.8</strong></a>
jdaggett@7060 6798
jdaggett@8279 6799 <li>sub, <a href="#sub" title=sub><strong>6.5</strong></a>
jdaggett@8279 6800
jdaggett@8279 6801 <li>super, <a href="#super" title=super><strong>6.5</strong></a>
jdaggett@8279 6802
jdaggett@8397 6803 <li>support, <a href="#support" title=support><strong>5.2</strong></a>
jdaggett@8397 6804
jdaggett@8225 6805 <li>swash, <a href="#swash" title=swash><strong>6.8</strong></a>
jdaggett@1662 6806
jdaggett@8363 6807 <li>system font fallback, <a href="#system-font-fallback" title="system
jdaggett@8363 6808 font fallback"><strong>5.2</strong></a>
jdaggett@8363 6809
jdaggett@1662 6810 <li>tabular-nums, <a href="#tabular-nums"
jdaggett@2118 6811 title=tabular-nums><strong>6.7</strong></a>
jdaggett@1662 6812
jdaggett@1662 6813 <li>titling-caps, <a href="#titling-caps"
jdaggett@2118 6814 title=titling-caps><strong>6.6</strong></a>
jdaggett@1856 6815
jdaggett@2504 6816 <li>traditional, <a href="#traditional"
jdaggett@2504 6817 title=traditional><strong>6.10</strong></a>
jdaggett@2118 6818
jdaggett@8278 6819 <li>ultra-condensed, <a href="#ultra-condensed"
jdaggett@8278 6820 title=ultra-condensed><strong>3.3</strong></a>
jdaggett@8278 6821
jdaggett@8278 6822 <li>ultra-expanded, <a href="#ultra-expanded"
jdaggett@8278 6823 title=ultra-expanded><strong>3.3</strong></a>
jdaggett@8278 6824
jdaggett@2118 6825 <li>unicase, <a href="#unicase" title=unicase><strong>6.6</strong></a>
jdaggett@1662 6826
jdaggett@1662 6827 <li>unicode-range, <a href="#descdef-unicode-range"
jdaggett@890 6828 title=unicode-range><strong>4.5</strong></a>
jdaggett@7311 6829
jdaggett@7311 6830 <li>weight, <a href="#weight" title=weight><strong>2</strong></a>
jdaggett@7311 6831
jdaggett@7311 6832 <li>width, <a href="#width" title=width><strong>2</strong></a>
jdaggett@484 6833 </ul>
jdaggett@484 6834 <!--end-index-->
jdaggett@484 6835
jdaggett@484 6836 <h2 class=no-num id=property-index>Property index</h2>
jdaggett@890 6837 <!--begin-properties-->
jdaggett@484 6838
jdaggett@484 6839 <table class=proptable>
jdaggett@484 6840 <thead>
jdaggett@484 6841 <tr>
jdaggett@484 6842 <th>Property
jdaggett@484 6843
jdaggett@484 6844 <th>Values
jdaggett@484 6845
jdaggett@484 6846 <th>Initial
jdaggett@484 6847
jdaggett@1148 6848 <th>Applies to
jdaggett@484 6849
jdaggett@484 6850 <th>Inh.
jdaggett@484 6851
jdaggett@484 6852 <th>Percentages
jdaggett@484 6853
jdaggett@484 6854 <th>Media
jdaggett@484 6855
jdaggett@484 6856 <tbody>
jdaggett@3460 6857 <tr>
jdaggett@3460 6858 <th><a class=property href="#propdef-font">font</a>
jdaggett@484 6859
jdaggett@8225 6860 <td>[ [ &lt;‘font-style’&gt; || &lt;font-variant-css21&gt; ||
jdaggett@8225 6861 &lt;‘font-weight’&gt; || &lt;‘font-stretch’ ]?
jdaggett@8225 6862 &lt;‘font-size’&gt; [ / &lt;‘line-height’&gt; ]?
jdaggett@8225 6863 &lt;‘font-family’&gt; ] | caption | icon | menu | message-box |
jdaggett@7020 6864 small-caption | status-bar
jdaggett@484 6865
jdaggett@484 6866 <td>see individual properties
jdaggett@484 6867
jdaggett@484 6868 <td>all elements
jdaggett@484 6869
jdaggett@484 6870 <td>yes
jdaggett@484 6871
jdaggett@484 6872 <td>see individual properties
jdaggett@484 6873
jdaggett@484 6874 <td>visual
jdaggett@484 6875
jdaggett@3460 6876 <tr>
jdaggett@8278 6877 <th><span class=property>font-family</span>
jdaggett@484 6878
jdaggett@8225 6879 <td>[ &lt;family-name&gt; | &lt;generic-family&gt; ] #
jdaggett@484 6880
jdaggett@484 6881 <td>depends on user agent
jdaggett@484 6882
jdaggett@484 6883 <td>all elements
jdaggett@484 6884
jdaggett@484 6885 <td>yes
jdaggett@484 6886
jdaggett@484 6887 <td>N/A
jdaggett@484 6888
jdaggett@484 6889 <td>visual
jdaggett@484 6890
jdaggett@3460 6891 <tr>
jdaggett@8279 6892 <th><span class=property>font-feature-settings</span>
jdaggett@1662 6893
jdaggett@8225 6894 <td>normal | &lt;feature-tag-value&gt; #
jdaggett@1662 6895
jdaggett@1662 6896 <td>normal
jdaggett@1662 6897
jdaggett@1662 6898 <td>all elements
jdaggett@1662 6899
jdaggett@1662 6900 <td>yes
jdaggett@1662 6901
jdaggett@1662 6902 <td>N/A
jdaggett@1662 6903
jdaggett@1662 6904 <td>visual
jdaggett@1662 6905
jdaggett@3460 6906 <tr>
jdaggett@3460 6907 <th><a class=property href="#propdef-font-kerning">font-kerning</a>
jdaggett@1662 6908
jdaggett@1856 6909 <td>auto | normal | none
jdaggett@1856 6910
jdaggett@1856 6911 <td>auto
jdaggett@1662 6912
jdaggett@1662 6913 <td>all elements
jdaggett@1662 6914
jdaggett@1662 6915 <td>yes
jdaggett@1662 6916
jdaggett@1662 6917 <td>N/A
jdaggett@1662 6918
jdaggett@1662 6919 <td>visual
jdaggett@1662 6920
jdaggett@3460 6921 <tr>
jdaggett@3460 6922 <th><a class=property
jdaggett@1732 6923 href="#propdef-font-language-override">font-language-override</a>
jdaggett@1662 6924
jdaggett@5809 6925 <td>normal | &lt;string&gt;
jdaggett@1662 6926
jdaggett@1662 6927 <td>normal
jdaggett@1662 6928
jdaggett@1662 6929 <td>all elements
jdaggett@1662 6930
jdaggett@1662 6931 <td>yes
jdaggett@1662 6932
jdaggett@1662 6933 <td>N/A
jdaggett@1662 6934
jdaggett@1662 6935 <td>visual
jdaggett@1662 6936
jdaggett@3460 6937 <tr>
jdaggett@3460 6938 <th><a class=property href="#propdef-font-size">font-size</a>
jdaggett@484 6939
jdaggett@8225 6940 <td>&lt;absolute-size&gt; | &lt;relative-size&gt; | &lt;length&gt; |
jdaggett@8225 6941 &lt;percentage&gt;
jdaggett@484 6942
jdaggett@484 6943 <td>medium
jdaggett@484 6944
jdaggett@484 6945 <td>all elements
jdaggett@484 6946
jdaggett@484 6947 <td>yes
jdaggett@484 6948
jdaggett@484 6949 <td>refer to parent element's font size
jdaggett@484 6950
jdaggett@484 6951 <td>visual
jdaggett@484 6952
jdaggett@3460 6953 <tr>
jdaggett@3460 6954 <th><a class=property
jdaggett@1662 6955 href="#propdef-font-size-adjust">font-size-adjust</a>
jdaggett@484 6956
jdaggett@8968 6957 <td>none | &lt;number&gt;
jdaggett@484 6958
jdaggett@484 6959 <td>none
jdaggett@484 6960
jdaggett@484 6961 <td>all elements
jdaggett@484 6962
jdaggett@484 6963 <td>yes
jdaggett@484 6964
jdaggett@554 6965 <td>N/A
jdaggett@484 6966
jdaggett@484 6967 <td>visual
jdaggett@484 6968
jdaggett@3460 6969 <tr>
jdaggett@8278 6970 <th><span class=property>font-stretch</span>
jdaggett@1662 6971
jdaggett@1662 6972 <td>normal | ultra-condensed | extra-condensed | condensed |
jdaggett@1662 6973 semi-condensed | semi-expanded | expanded | extra-expanded |
jdaggett@5809 6974 ultra-expanded
jdaggett@484 6975
jdaggett@484 6976 <td>normal
jdaggett@484 6977
jdaggett@484 6978 <td>all elements
jdaggett@484 6979
jdaggett@484 6980 <td>yes
jdaggett@484 6981
jdaggett@484 6982 <td>N/A
jdaggett@484 6983
jdaggett@484 6984 <td>visual
jdaggett@484 6985
jdaggett@3460 6986 <tr>
jdaggett@8278 6987 <th><span class=property>font-style</span>
jdaggett@484 6988
jdaggett@5809 6989 <td>normal | italic | oblique
jdaggett@484 6990
jdaggett@484 6991 <td>normal
jdaggett@484 6992
jdaggett@484 6993 <td>all elements
jdaggett@484 6994
jdaggett@484 6995 <td>yes
jdaggett@484 6996
jdaggett@484 6997 <td>N/A
jdaggett@484 6998
jdaggett@484 6999 <td>visual
jdaggett@484 7000
jdaggett@3460 7001 <tr>
jdaggett@3460 7002 <th><a class=property href="#propdef-font-synthesis">font-synthesis</a>
jdaggett@2487 7003
jdaggett@2487 7004 <td>none | [ weight || style ]
jdaggett@2487 7005
jdaggett@2487 7006 <td>weight style
jdaggett@2457 7007
jdaggett@2457 7008 <td>all elements
jdaggett@2457 7009
jdaggett@2457 7010 <td>yes
jdaggett@2457 7011
jdaggett@2457 7012 <td>N/A
jdaggett@2457 7013
jdaggett@2457 7014 <td>visual
jdaggett@2457 7015
jdaggett@3460 7016 <tr>
jdaggett@8278 7017 <th><span class=property>font-variant</span>
jdaggett@1662 7018
jdaggett@6436 7019 <td>normal | none | [ &lt;common-lig-values&gt; ||
jdaggett@3460 7020 &lt;discretionary-lig-values&gt; || &lt;historical-lig-values&gt; ||
jdaggett@3041 7021 &lt;contextual-alt-values&gt; || stylistic(&lt;feature-value-name&gt;)
jdaggett@8225 7022 || historical-forms || styleset(&lt;feature-value-name&gt; #) ||
jdaggett@8225 7023 character-variant(&lt;feature-value-name&gt; #) ||
jdaggett@5833 7024 swash(&lt;feature-value-name&gt;) ||
jdaggett@3041 7025 ornaments(&lt;feature-value-name&gt;) ||
jdaggett@4545 7026 annotation(&lt;feature-value-name&gt;) || [ small-caps | all-small-caps
jdaggett@6648 7027 | petite-caps | all-petite-caps | unicase | titling-caps ] ||
jdaggett@2509 7028 &lt;numeric-figure-values&gt; || &lt;numeric-spacing-values&gt; ||
jdaggett@3638 7029 &lt;numeric-fraction-values&gt; || ordinal || slashed-zero ||
jdaggett@3638 7030 &lt;east-asian-variant-values&gt; || &lt;east-asian-width-values&gt; ||
jdaggett@3638 7031 ruby ]
jdaggett@484 7032
jdaggett@484 7033 <td>normal
jdaggett@484 7034
jdaggett@484 7035 <td>all elements
jdaggett@484 7036
jdaggett@484 7037 <td>yes
jdaggett@484 7038
jdaggett@7377 7039 <td>see individual properties
jdaggett@484 7040
jdaggett@484 7041 <td>visual
jdaggett@484 7042
jdaggett@3460 7043 <tr>
jdaggett@3460 7044 <th><a class=property
jdaggett@1662 7045 href="#propdef-font-variant-alternates">font-variant-alternates</a>
jdaggett@1662 7046
jdaggett@6176 7047 <td>normal | [ stylistic(&lt;feature-value-name&gt;) || historical-forms
jdaggett@8225 7048 || styleset(&lt;feature-value-name&gt; #) ||
jdaggett@8225 7049 character-variant(&lt;feature-value-name&gt; #) ||
jdaggett@5833 7050 swash(&lt;feature-value-name&gt;) ||
jdaggett@3638 7051 ornaments(&lt;feature-value-name&gt;) ||
jdaggett@3638 7052 annotation(&lt;feature-value-name&gt;) ]
jdaggett@1662 7053
jdaggett@1662 7054 <td>normal
jdaggett@1662 7055
jdaggett@1662 7056 <td>all elements
jdaggett@1662 7057
jdaggett@1662 7058 <td>yes
jdaggett@1662 7059
jdaggett@1662 7060 <td>N/A
jdaggett@1662 7061
jdaggett@1662 7062 <td>visual
jdaggett@1662 7063
jdaggett@3460 7064 <tr>
jdaggett@3460 7065 <th><a class=property
jdaggett@1662 7066 href="#propdef-font-variant-caps">font-variant-caps</a>
jdaggett@1662 7067
jdaggett@5809 7068 <td>normal | small-caps | all-small-caps | petite-caps | all-petite-caps
jdaggett@6648 7069 | unicase | titling-caps
jdaggett@1662 7070
jdaggett@1662 7071 <td>normal
jdaggett@1662 7072
jdaggett@1662 7073 <td>all elements
jdaggett@1662 7074
jdaggett@1662 7075 <td>yes
jdaggett@1662 7076
jdaggett@1662 7077 <td>N/A
jdaggett@1662 7078
jdaggett@1662 7079 <td>visual
jdaggett@1662 7080
jdaggett@3460 7081 <tr>
jdaggett@3460 7082 <th><a class=property
jdaggett@1662 7083 href="#propdef-font-variant-east-asian">font-variant-east-asian</a>
jdaggett@1662 7084
jdaggett@5809 7085 <td>normal | [ &lt;east-asian-variant-values&gt; ||
jdaggett@3638 7086 &lt;east-asian-width-values&gt; || ruby ]
jdaggett@1662 7087
jdaggett@1662 7088 <td>normal
jdaggett@1662 7089
jdaggett@1662 7090 <td>all elements
jdaggett@1662 7091
jdaggett@1662 7092 <td>yes
jdaggett@1662 7093
jdaggett@1662 7094 <td>N/A
jdaggett@1662 7095
jdaggett@1662 7096 <td>visual
jdaggett@1662 7097
jdaggett@3460 7098 <tr>
jdaggett@3460 7099 <th><a class=property
jdaggett@1662 7100 href="#propdef-font-variant-ligatures">font-variant-ligatures</a>
jdaggett@1662 7101
jdaggett@8225 7102 <td>normal | none | [ &lt;common-lig-values&gt; ||
jdaggett@8225 7103 &lt;discretionary-lig-values&gt; || &lt;historical-lig-values&gt; ||
jdaggett@8225 7104 &lt;contextual-alt-values&gt; ]
jdaggett@1662 7105
jdaggett@1662 7106 <td>normal
jdaggett@1662 7107
jdaggett@1662 7108 <td>all elements
jdaggett@1662 7109
jdaggett@1662 7110 <td>yes
jdaggett@1662 7111
jdaggett@1662 7112 <td>N/A
jdaggett@1662 7113
jdaggett@1662 7114 <td>visual
jdaggett@1662 7115
jdaggett@3460 7116 <tr>
jdaggett@3460 7117 <th><a class=property
jdaggett@1662 7118 href="#propdef-font-variant-numeric">font-variant-numeric</a>
jdaggett@1662 7119
jdaggett@5809 7120 <td>normal | [ &lt;numeric-figure-values&gt; ||
jdaggett@1732 7121 &lt;numeric-spacing-values&gt; || &lt;numeric-fraction-values&gt; ||
jdaggett@3638 7122 ordinal || slashed-zero ]
jdaggett@1662 7123
jdaggett@1662 7124 <td>normal
jdaggett@1662 7125
jdaggett@1662 7126 <td>all elements
jdaggett@1662 7127
jdaggett@1662 7128 <td>yes
jdaggett@1662 7129
jdaggett@1662 7130 <td>N/A
jdaggett@1662 7131
jdaggett@1662 7132 <td>visual
jdaggett@1662 7133
jdaggett@3460 7134 <tr>
jdaggett@3460 7135 <th><a class=property
jdaggett@3460 7136 href="#propdef-font-variant-position">font-variant-position</a>
jdaggett@3460 7137
jdaggett@3638 7138 <td>normal | sub | super
jdaggett@3460 7139
jdaggett@3460 7140 <td>normal
jdaggett@3460 7141
jdaggett@3460 7142 <td>all elements
jdaggett@3460 7143
jdaggett@3460 7144 <td>yes
jdaggett@3460 7145
jdaggett@3460 7146 <td>N/A
jdaggett@3460 7147
jdaggett@3460 7148 <td>visual
jdaggett@3460 7149
jdaggett@3460 7150 <tr>
jdaggett@8278 7151 <th><span class=property>font-weight</span>
jdaggett@484 7152
jdaggett@484 7153 <td>normal | bold | bolder | lighter | 100 | 200 | 300 | 400 | 500 | 600
jdaggett@5809 7154 | 700 | 800 | 900
jdaggett@484 7155
jdaggett@484 7156 <td>normal
jdaggett@484 7157
jdaggett@484 7158 <td>all elements
jdaggett@484 7159
jdaggett@484 7160 <td>yes
jdaggett@484 7161
jdaggett@484 7162 <td>N/A
jdaggett@484 7163
jdaggett@484 7164 <td>visual
jdaggett@484 7165 </table>
jdaggett@890 7166 <!--end-properties-->
jdaggett@5596 7167 <!--begin-descriptors-->
jdaggett@5596 7168
jdaggett@5596 7169 <table class=proptable>
jdaggett@5596 7170 <thead>
jdaggett@5596 7171 <tr>
jdaggett@5596 7172 <th>Descriptor
jdaggett@5596 7173
jdaggett@5596 7174 <th>Value
jdaggett@5596 7175
jdaggett@5596 7176 <th>Initial
jdaggett@5596 7177
jdaggett@5596 7178 <th>Percentages
jdaggett@5596 7179
jdaggett@5596 7180 <th>Media
jdaggett@5596 7181
jdaggett@5596 7182 <tbody>
jdaggett@5596 7183 <tr>
jdaggett@8278 7184 <th><span class=property>font-family</span>
jdaggett@5596 7185
jdaggett@8225 7186 <td>&lt;family-name&gt;
jdaggett@5596 7187
jdaggett@5596 7188 <td>N/A
jdaggett@5596 7189
jdaggett@5596 7190 <tr>
jdaggett@8279 7191 <th><span class=property>font-feature-settings</span>
jdaggett@5596 7192
jdaggett@8225 7193 <td>normal | &lt;feature-tag-value&gt; #
jdaggett@5596 7194
jdaggett@5596 7195 <td>normal
jdaggett@5596 7196
jdaggett@5596 7197 <tr>
jdaggett@8278 7198 <th><span class=property>font-stretch</span>
jdaggett@5596 7199
jdaggett@5596 7200 <td>normal | ultra-condensed | extra-condensed | condensed |
jdaggett@5596 7201 semi-condensed | semi-expanded | expanded | extra-expanded |
jdaggett@5596 7202 ultra-expanded
jdaggett@5596 7203
jdaggett@5596 7204 <td>normal
jdaggett@5596 7205
jdaggett@5596 7206 <tr>
jdaggett@8278 7207 <th><span class=property>font-style</span>
jdaggett@5596 7208
jdaggett@5596 7209 <td>normal | italic | oblique
jdaggett@5596 7210
jdaggett@5596 7211 <td>normal
jdaggett@5596 7212
jdaggett@5596 7213 <tr>
jdaggett@8278 7214 <th><span class=property>font-variant</span>
jdaggett@5596 7215
jdaggett@8225 7216 <td>normal | none | [ &lt;common-lig-values&gt; ||
jdaggett@5596 7217 &lt;discretionary-lig-values&gt; || &lt;historical-lig-values&gt; ||
jdaggett@5596 7218 &lt;contextual-alt-values&gt; || stylistic(&lt;feature-value-name&gt;)
jdaggett@8225 7219 || historical-forms || styleset(&lt;feature-value-name&gt; #) ||
jdaggett@8225 7220 character-variant(&lt;feature-value-name&gt; #) ||
jdaggett@5833 7221 swash(&lt;feature-value-name&gt;) ||
jdaggett@5596 7222 ornaments(&lt;feature-value-name&gt;) ||
jdaggett@5596 7223 annotation(&lt;feature-value-name&gt;) || [ small-caps | all-small-caps
jdaggett@6648 7224 | petite-caps | all-petite-caps | unicase | titling-caps ] ||
jdaggett@5596 7225 &lt;numeric-figure-values&gt; || &lt;numeric-spacing-values&gt; ||
jdaggett@5596 7226 &lt;numeric-fraction-values&gt; || ordinal || slashed-zero ||
jdaggett@5596 7227 &lt;east-asian-variant-values&gt; || &lt;east-asian-width-values&gt; ||
jdaggett@5596 7228 ruby ]
jdaggett@5596 7229
jdaggett@5596 7230 <td>normal
jdaggett@5596 7231
jdaggett@5596 7232 <tr>
jdaggett@8278 7233 <th><span class=property>font-weight</span>
jdaggett@5596 7234
jdaggett@5596 7235 <td>normal | bold | 100 | 200 | 300 | 400 | 500 | 600 | 700 | 800 | 900
jdaggett@5596 7236
jdaggett@5596 7237 <td>normal
jdaggett@5596 7238
jdaggett@5596 7239 <tr>
jdaggett@5596 7240 <th><a class=property href="#descdef-src">src</a>
jdaggett@5596 7241
jdaggett@8225 7242 <td>[ &lt;url> [format(&lt;string> #)]? | &lt;font-face-name&gt; ] #
jdaggett@5596 7243
jdaggett@5596 7244 <td>N/A
jdaggett@5596 7245
jdaggett@5596 7246 <tr>
jdaggett@5596 7247 <th><a class=property href="#descdef-unicode-range">unicode-range</a>
jdaggett@5596 7248
jdaggett@8225 7249 <td>&lt;urange&gt; #
jdaggett@5596 7250
jdaggett@5596 7251 <td>U+0-10FFFF
jdaggett@5596 7252 </table>
jdaggett@5596 7253 <!--end-descriptors-->
jdaggett@6648 7254 <script type="text/javascript">
jdaggett@6648 7255 window.onload = function () {
jdaggett@6648 7256 if (!("devicePixelRatio" in window && window.devicePixelRatio > 1)) return;
jdaggett@6648 7257 var i, hiresElements = document.getElementsByClassName("hires");
jdaggett@6648 7258 for (i = 0; i < hiresElements.length; i++) {
jdaggett@6648 7259 var h = hiresElements[i];
jdaggett@6648 7260 if (h.tagName != "IMG") continue;
jdaggett@6648 7261 var src = h.getAttribute("src");
jdaggett@6648 7262 var src2x = src.replace(/\.\w+$/, function(m) { return "@2x" + m; });
jdaggett@6648 7263 h.src = src2x;
jdaggett@6648 7264 }
jdaggett@6648 7265 }
jdaggett@6648 7266 </script>
jdaggett@484 7267 </html>
jdaggett@484 7268 <!-- Keep this comment at the end of the file
jdaggett@484 7269 Local variables:
jdaggett@484 7270 mode: sgml
jdaggett@484 7271 sgml-declaration:"~/SGML/HTML4.decl"
jdaggett@484 7272 sgml-default-doctype-name:"html"
jdaggett@484 7273 sgml-minimize-attributes:t
jdaggett@484 7274 sgml-nofill-elements:("pre" "style" "br")
jdaggett@484 7275 sgml-live-element-indicator:t
jdaggett@484 7276 sgml-omittag:nil
jdaggett@484 7277 sgml-shorttag:nil
jdaggett@484 7278 sgml-namecase-general:t
jdaggett@484 7279 sgml-general-insert-case:lower
jdaggett@484 7280 sgml-always-quote-attributes:t
jdaggett@484 7281 sgml-indent-step:nil
jdaggett@484 7282 sgml-indent-data:t
jdaggett@484 7283 sgml-parent-document:nil
jdaggett@484 7284 sgml-exposed-tags:nil
jdaggett@484 7285 sgml-local-catalogs:nil
jdaggett@484 7286 sgml-local-ecat-files:nil
jdaggett@484 7287 End:
jdaggett@484 7288 -->
jdaggett@8277 7289 <!--
jdaggett@1856 7290
jdaggett@1856 7291 to do:
jdaggett@1856 7292
jdaggett@1856 7293 - wording of OpenType family name handling
jdaggett@1856 7294 - handling combining sequences in the font matching algorithm
jdaggett@1856 7295 - fix-up fi ligature example
jdaggett@1856 7296
jdaggett@1856 7297 -->

mercurial