An element domain vocabulary module defines element types that are appropriate for the subject-matter or application domain for which they are designed. The purpose is usually to enhance the user's interaction by providing "semantic" elements whose names more accurately denote their content, making that content easier to search and retrieve.
Domain entity file
In addition to the domain declaration entity, the entity declaration file for element domain modules must include the following components:
- Element extension entity
The declaration (.ent) file must define an entity for each element extended by the domain. The base of the entity name is the abbreviation for the domain and the extension of the entity name is the name of the extended element. For example, the highlight domain (abbreviated as hi-d) extends the ph element, so the entity for the extended element is named hi-d-ph.
The value of the entity is a disjunctive list of the specialized elements that are intended to occur in the same locations as the extended element.
For example, the hi-d-ph entity is defined as follows:
<!ENTITY % hi-d-ph "b | u | i | tt | sup | sub">