This section explains how to implement XML Schema (XSD) based document-type shells,
specializations, and constraints.
XML Schema: Overview and limitations of coding requirements
DITA coding practices for XML Schema rely on the XSD redefine facility in order to implement specializations or constraints. However, limitations in the redefine facility can present problems for some DITA modules implemented in XML Schema.
XML Schema: Coding requirements for structural modules
An XSD structural module declares a top-level map or topic type. It is implemented as a pair of XSD documents, one that defines groups used to integrate and override the type and one that defines the element types specific to the type.
XML Schema: Coding requirements for constraint modules
A structural constraint module defines the constraints for a map or topic element type. A domain constraint module defines the constraints for an element or attribute domain.