--- a/rdf-primer/index.html	Mon Nov 11 17:55:21 2013 +0100
+++ b/rdf-primer/index.html	Mon Nov 11 18:53:04 2013 +0100
@@ -279,10 +279,10 @@
     <p>The abbreviation IRI is short for "International Resource
     Identifier".  An IRI identifies a Web resource. IRIs are
     generalization of URIs (Uniform Resource Indeitfiers), allowing
-    non-ASCII characters to be used in the IRI character string.</p>
+    non-ASCII characters to be used in the IRI character string. IRIs are specified
+    in RFC 3987 [[!RFC3987]]. 
 
-    <p>IRIs can appear in all three positions of an RDF statement and are specified
-    in RFC 3987 [[!RFC3987]]. </p>
+    <p class="highlight">IRIs can appear in all three positions of an RDF statement. </p>
 
     <p>IRIs can be used to identify both documents
     (e.g. a Web page) and things (e.g. a person). 
@@ -305,11 +305,11 @@
 
       <pre class="example">http://data.europeana.eu/item/04802/243FA8618938F4117025F17A8B813C5F9AA4D619</pre>
 
-    <p "note">RDF is agnositc about what the IRI stands for. However,
+    <p class="note">RDF is agnositc about what the IRI stands for. However,
     IRIS may be given meaning by particular vocabularies or
-    conventions. VIAF (see example above) is an example of this. RDF
+    conventions. VIAF (see example above) is an example of such a vocabulry. RDF
     vocabularies are discussed in more detail in Sec. <a
-    href=#section-RDF-Schema""RDF vocabularies"</a>. </p>
+    href="#section-RDF-Schema">"RDF vocabularies"</a>. </p>
     
     </section>
 
@@ -317,22 +317,52 @@
 
       <h3>Literal</h3>
 
-      <p>Literals can appear in the object position of an RDF statement. Examples of literals include
+      <p>Literals are basic values that are not IRIs. Examples of literals include
       strings such as "La Joconde", dates such as "the 4th of July, 1990" and numbers such as "3.14159". 
-      Litterals are associated with a <i>datatype</i> enabling such values to be parsed and interpreted correctly. 
-      Strings can optionally be associated with a <i>language tag</i>. For example "Léonard de Vinci" could
+      Litterals are associated with a <i>datatype</i> enabling such
+      values to be parsed and interpreted correctly.  
+      String literals can optionally be associated with a <i>language
+      tag</i>. For example "Léonard de Vinci" could 
       be associated with the "fr" language tag and "李奥纳多·达·文西" with the "zh" language tag.</p>
-   
+
+      <p>Literals can only appear in the object position of an RDF
+      statement.</p>
+
+     <p>The RDF Concepts document provides a
+     <a href="http://www.w3.org/TR/rdf11-concepts/#section-Datatypes">list
+     of datatypes</a>.  This includes most datatypes defined by XML
+     Schema, such as string, boolean, integer, decimal and date. </p>
+
+     <p class="note">The 2004 version of RDF contained the notion of a
+     "plain lieral" with no datatype. This feature has been removed as the
+     distinction between "plain" literals and literals with datatype
+     "string" was confusing. RDF syntaxes such as Turtle allow
+     writing literals without an explicit datatype, but this is
+     syntactic sugar for a string datatype.</p>
+
     </section>
 
     <section id="subsection-blank-node">
 
       <h3>Blank node</h3>
 
+      <p>IRIS and literals together provide the basic material for
+      writing down RDF statements. In addition, it is sometimes handy to
+      be able to talk about anonymous resources. For example, we might
+      want to state that "the Mona Lisa was created by X" and that "X
+      was born in Vinci". Anonymous resources such as "X" are called "blank
+      nodes" in RDF. </p>
+
       <p>Blank nodes can appear in the subject and object position of an RDF statement. They can be used
-      to denote resources without explicitly naming them with an IRI. For example a blank node could be
-      used to express that the "Mona Lisa" painting has been created by someone whose name is "Leonardo da Vinci"
-      without necessarily identifying him with an IRI.</p>
+      to denote resources without explicitly naming them with an
+      IRI.</p>
+
+      <p class="note">Blank nodes can kae RDF look very complicated,
+      especially when one consults details in the RDF Concepts
+      [[RDF11-CONCEPTS]] and RDF Semantics [[RDF11-MT]] document. It
+      should be noted that many RDF users survive without ever having
+      to deal with blank nodes. </p> 
+
    
     </section>