Namespaces Scorecard

Language Feature DTDs RELAX NG Schematron W3C XML Schemas
Namespace support Some[a] Yes Yes Yes
Explicit namespaces Some[a] Yes Yes Yes
Any namespace No Yes Yes Yes
Any namespace (XSL) No Yes Yes No
Any namespace (nesting) No Yes Yes Yes

[a] Namespace prefixes are fixed on a per-document basis at best.