Looking for best generic language to refer to DTD, XSD, and RELAX NG in the DITA 1.3 spec

[Kristen James Eberlein <kris@eberleinconsulting.com>]

With the advent of support for RELAX NG, we either need to insert RELAX NG everywhere in the spec that we refer to "DTD and XSD," or we need to find a good, generic alternative.

Here is a typical paragraph that I would like to revise using a generic term; I've highlighted in red bold the places that I want to make generic (or have attempted to make generic):

" DITA does not require that conforming DITA documents have an associated document-type definition as long as all required attributes are explicit in the document instances. However, most DITA documents have an associated DTD, RELAX NG, or XML Schema document. Such associated documents enable validation using normal XML processors; they also can provide default values for the @domains and @class attributes. While the DITA specification only defines coding requirements for DTD, RELAX NG, and XML Schema documents, conforming DITA documents MAY use other document-type constraint languages, such as Schematron."

What is the best choice for an generic term? "XML schema language" or simply "schema"?

I also want to replace the adjective "constraint" in the last sentence; I've highlighted it in blue bold. Any suggestions?

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Best,
Kris

Kristen James Eberlein
Chair, OASIS DITA Technical Committee
Principal consultant, Eberlein Consulting
www.eberleinconsulting.com
+1 919 682-2290; kriseberlein (skype)