About XHTML Modularization

XHTML 1.0 specifies three XML document types that correspond to the three HTML 4 DTDs: Strict, Transitional, and Frameset. XHTML 1.0 is the basis for a family of document types that subset and extend HTML.

XHTML Modularization is a decomposition of XHTML 1.0, into a collection of abstract modules that provide specific types of functionality. These abstract modules are implemented using the XML Document Type Definition language. The modules may be combined with each other and with other modules to create XHTML subset and extension document types.

Some definitions of terms:

• abstract module - a unit of document type specification corresponding to a distinct type of content, corresponding to a markup construct reflecting this distinct type.
• module - an abstract unit within a document model expressed as a DTD fragment, used to consolidate markup declarations to increase the flexibility, modifiability, reuse and understanding of specific logical or semantic structures.
• modularization - an implementation of a modularization model; the process of composing or de-composing a DTD by dividing its markup declarations into units or groups to support specific goals. Modules may or may not exist as separate file entities (i.e., the physical and logical structures of a DTD may mirror each other, but there is no such requirement).
• modularization model - the abstract design of the document type definition (DTD) in support of the modularization goals, such as reuse, extensibility, expressiveness, ease of documentation, code size, consistency and intuitiveness of use.