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

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?

    

    
    
-- 

      Best,

      Kris

      

      Kristen James Eberlein

      Chair, OASIS DITA Technical Committee

      Principal consultant, Eberlein Consulting

      www.eberleinconsulting.com

      +1 919 682-2290; kriseberlein (skype)