--- a/ontology/ProvenanceOntology.owl	Mon Apr 23 09:15:41 2012 +0100
+++ b/ontology/ProvenanceOntology.owl	Mon Apr 23 11:19:43 2012 +0100
@@ -56,11 +56,15 @@
     <owl:AnnotationProperty rdf:about="&prov;inverse"/>
     <owl:AnnotationProperty rdf:about="&rdfs;comment"/>
     <owl:AnnotationProperty rdf:about="&rdfs;seeAlso"/>
-    <owl:AnnotationProperty rdf:about="&prov;category"/>
+    <owl:AnnotationProperty rdf:about="&prov;category">
+	<rdfs:comment xml:lang="en">Classify prov-o terms into three categories, including starting-point, qualifed, and extended. This classification is used to gently introduce prov-o terms to its users. </rdfs:comment>
+    </owl:AnnotationProperty>
     <owl:AnnotationProperty rdf:about="&prov;prov-dm-constraints">
         <rdfs:subPropertyOf rdf:resource="&rdfs;seeAlso"/>
     </owl:AnnotationProperty>
-    <owl:AnnotationProperty rdf:about="&prov;component"/>
+    <owl:AnnotationProperty rdf:about="&prov;component">
+	<rdfs:comment xml:lang="en">Classify prov-o terms into six components according to prov-dm, including . This classification is used so that readers of prov-o specification can find its correspondence with the prov-dm specification.</rdfs:comment> 
+    </owl:AnnotationProperty>
     <owl:AnnotationProperty rdf:about="&prov;qualifiedForm">
         <rdfs:comment xml:lang="en">This annotation property links a prov:involved subproperty with a prov:Involved subclass. This indicates that the property can be qualified by using prov:qualified.