GLs seem wrong about commonness of co-occurrence

[sydb]

Chapter TD states “… the attribute passive may be supplied only if the attribute active is supplied.. Few schema language support co-occurence constraints such as the latter.”

Few? Probably technically true given how many schema languages are in existence, but since 3 of the big 4 (RELAX NG, Schematron, XSD > 1.0) do support it, it seems a bit of an odd thing to say.

[martinascholger]

How about a rewording like (instead of "Few schema language support co-occurence constraints such as the latter"):

"The schema languages RELAX NG, Schematron and XML Schema 1.1 support co-occurence constraints such as the latter."

[ebeshero]

Is the sentence about schema validation of co-occurrence constraints even necessary here?

[raffazizzi]

F2F subgroup agrees with @ebeshero that the sentence should just be cut.