Provide a schema for Atom documents in the spec.
Providing a schema, as either a normative or non-normative appendix, will aid readers.
I propose that the spec provide both a RELAX NG grammar and an W3C XML Schema. If there's agreement that a schema should be provided, I'll work to see that one gets added here.
Sample W3C XML Schema. This schema is used by both the WSDL 1.1 and 2.0 API definitions. -- Randy Charles Morin
An ASN.1 schema should also be provided. -- BobWyman