Hi, Eliot.
In 1.3, we did deliberately decide to omit @keyscope from subject scheme maps. Robert and Chris Nitchie strongly advocated for this approach; I had some reservations because the subject scheme map for the spec actually would have benefitted from @keyscope.
We could discuss this from DITA 2.0, but it is very late in the design process ...
Kris
------------------------------
Kristen Eberlein
Eberlein Consulting LLC
Durham NC
919-622-1501
------------------------------