Note that context-{fill,stroke} means to use the same coordinate system of the referenced element.
--- a/master/painting.html Fri Jan 18 12:37:14 2013 +1100
+++ b/master/painting.html Fri Jan 18 13:35:06 2013 +1100
@@ -148,9 +148,12 @@
<dt>context-fill</dt>
<dt>context-stroke</dt>
- <dd>The computed value of the <a>'fill'</a> or <a>'stroke'</a>
+ <dd>The same paint as the computed value of the <a>'fill'</a> or <a>'stroke'</a>
property, respectively, of the <a>context element</a>. If there
- is no context element, then no paint is applied.</dd>
+ is no context element, then no paint is applied. If the referenced paint
+ is a gradient or a pattern, then the coordinate space to use and the
+ object used for any <span class='attr-value'>'objectBoundingBox'</span>-relative
+ values are the same as those of the <a>context element</a>.</dd>
</dl>
</div>