On the face of it, what you need are the att.datcat attributes:
but they're not currently available on <equiv>. I don't see why they shouldn't be, so if you also think they're the right way to do this, let me know and I'll open a feature request.
I'm wondering if any linguistically oriented
TEI people of with knowledge of/experience with using
ISOcat and ODD could tell me if I am using the 'equiv' element correctly..
Below is an example of my 'elementSpec' in the ODD, I am looking to declare that the TEI element 'orth' is equivalent to the ISOcat value
'orthography' and whose PID is the value in the @uri:
<desc>The Mixtec working orthography is the orthographic system adhered to in this corpus and it corresponds to that used in the publications by
SIL Mexico which are based on the recommendations by <orgName
Savi</orgName> (House of the Mixtec language) for a unified orthographical system for all varieties of the Mixtec language. The value of the attribute @<att>uri</att>
is that defined in the ISOcat registry and pertains to a non-language specific orthographic system.</desc>
Any comments, advice would be much appreciated!
Thanks in advance,