On 27/03/17 13:33, Martin Holmes wrote: > Hi Lou, > >> You *can* use @when together with (say) @notAfter if you don't invoke >> schematron validation. > > and you *can* use <anyoldthing> inside <TEI> if you don't invoke > RelaxNG validation. Except that validation against a RelaxNG schema is explicitly part of our conformance definition, and validation against IsoSchematron isn't, or not so far as I can see. Hence my question. > > As far as I remember, the decision to express a constraint in a > Schematron rule as opposed to a construct that translates into RelaxNG > has never been made on the basis of the rule's supposed regulatory > force (for want of a better way of putting it); it's always been made > on the basis of practicality (we can't do this [yet] in ODD/RelaxNG). > Therefore I don't believe it makes sense to say that these constraints > are in any way less significant than regular constraints, except in > the case of deprecation warnings, which are explicitly warnings rather > than errors. > OK, thanks, that's an answer to my question. I'm not sure if I entirely agree with it -- it would enable us to side step birnbaum very easily -- but that's not relevant.