The category element represents any category by which a topic might be classified for retrieval or navigation. For example, the categories could be used to group topics in a generated navigation bar. Topics can belong to multiple categories.
Such classifications are likely to come from an enumerated or hierarchical set.
This element is equivalent to both the Coverage element and the Subject element in Dublin Core.
See appendix for information about this element in OASIS document type shells.
<prolog> <metadata> <category>Things that are blue</category> </metadata> </prolog>
The following attributes are available on this element: Universal attribute group.