DITA Generator -

structural specialization: The specialization feature of DITA allows for the creatio of new element types and attributes that are explicitly and formally derived from existing types in a way that allows for the blind interchange of all conforming DITA content and a minimum level of common processing for all DITA content.; Specialization DTD can be used to create a base for a structural type spcialization with the correct naming and modularization conventions. This base can then manually edited to define the element level specialization details.
shell DTD: A shell DTD defines the set of structural modules (topic or map types), domain modules, and constraints modules that the map or topic can use. In general, any production use of DITA involves definition of the set of modules best suited to local requirements. This always requires the creation of local shell document types, even if all they do is omit unneeded modules or apply constraints to the standard DITA-defined vocabulary.; See article about the benefits of creating local shells.
domain attribute specialization: Domain attribute specialization allows DITA document type developers to incorporate new conditional processing attributes that can be used for filtering and flagging, or new attributes with no existing equivalent that can be managed and generalized in the same way as conditional processing attributes.

PDF style plug-in
: Defines a new DITA-OT transformation type based on the built-in PDF conversion.; NOTE: PDF plug-in generator has moved to http://dita-generator.elovirta.com/.