Inside <constraintSpec> in P5 the encoding of the names of XML constructs is inconsistent. (As is the use of an initial capital and a trailing period.) I believe that this should be made consistent using the standard TEI constructs: <gi>, <att>, and <val>.
Note that doing so will not break current ODD processing,although no advantage will be gained on output (except consistency :-). This is because currently the contents of TEI element children of Schematron elements are passed along, but the tags are dropped. But in the future properly processing these constructs could be added as a feature.
As an example, I intend to check-in a new Schematron rule added to the <app> element (to enforce the “1-<lem>” rule expressed in prose in the <remarks> for <rdgGrp>) which makes use of TEI phrase-level encoding of XML construct names.