Use case for key scopes within subjectScheme maps

OK, I just ran into a use case for using key scopes in a
      subjectScheme map to define controlled values. The DITA 1.3 spec
      subjectScheme map, to be precise.

      

      I added a <subjectdef> for values used on @otherprops, and
      used a <enumerationdef>to control the permitted values for
      @otherprops.

      

      oXygen immediately told me that NO values were permitted for
      @otherprops. After scratching my head -- Why did oXygen think that
      I had an <enumerationdef> element with an empty
      <attributedef>? -- I went looking for key duplication, and
      it turned out that I had a collision between two keys named
      "example", one for @outputclass and now another for @otherprops.

      

      I could see that the following (slimmed down) map would be useful,
      if one used the attribute value of "example" for both @outputclass
      and @otherprops. (For the point of view of simplifying the
      authoring experience, I like to keep attribute values as simple
      and consistent as possible.)

      

      <?xml
        version="1.0" encoding="UTF-8"?>

        <!DOCTYPE subjectScheme PUBLIC "-//OASIS//DTD DITA Subject
        Scheme Map//EN" "subjectScheme.dtd">

        <subjectScheme>

        

        <subjectdef keys="outputclass-values">

                <subjectdef keys="cover"/>

                <subjectdef keys="example"/>

            </subjectdef>

            

            <subjectdef keys="otherprops-values"
        keyscope="otherprops">

                <subjectdef keys="example"/>

            </subjectdef>

        

         <enumerationdef>

                <attributedef name="outputclass"/>

                <subjectdef keyref="outputclass-values"/>

            </enumerationdef>

            

            <enumerationdef>

                <attributedef name="otherprops"/>

                <subjectdef
        keyref="otherprops.otherprops-values"/>

            </enumerationdef>

        

        </subjectScheme>

      

        

        -- 

        Best,

        Kris

        

        Kristen James Eberlein

        Chair, OASIS DITA Technical Committee

        Principal consultant, Eberlein Consulting

        www.eberleinconsulting.com

        +1 919 682-2290; kriseberlein (skype)