Prose and grammar may be not in synch

[xml-project]

The specs says on schematypens´:

The namespace of the schema may be given in the attribute schematypens.

I take the may to mean, that the attribute is optional but the grammar says it is mandatory. So either "schematypens" must be used to give the namespace of the schema or some prose should be added what else to put in that attribute. As the grammar defines it as xs:anyURI the choices are pretty restricted.

[gimsieke]

I think it’s an omission in the grammar. It should be optional.