Use the <topicSubjectHeader> element to supply a header
row for a topic classification table when you want to encourage classification with
different categories (also known as a facet classification). Each cell in the header
the subject for a different category. As a best practice, the subjects in the same column within the classification rows
must appear in the category in the subject scheme. For instance, if the cell within
the header row
specifies the Operating System category, the subjects in the column must be kinds
See appendix for information about this element in OASIS document type shells.
For a complete example in the context of the
<topicSubjectTable>, see Example.