ded:Definition: An element under the subjectCoverage element that specifies the
subject matter by a qualified entry from a controlled vocabulary. Specification
of the subject matter by a qualified entry from a controlled vocabulary. See IRM
Spec Category: Subject.
ded:Obligation: (Conditional) Mandatory to have at least one of category or
keyword.
ded:Comment: The number of category elements that can be included in the
subjectCoverage element is unbounded. When there are more than one category
element the additional category entries must occur before any keyword elements.
The category element can be marked according to SMP guidelines.