XML Schema

XML Schema is a proposed replacement for DTDs, which allows one to exercise more control over, for example, the types of data within elements.

XML Schema Status: W3C Recommendation, 2 May 2001

• Specs: Part 0: Primer, Part 1: Structure, Part 2: Datatypes.
• Schema FAQ.
• Alternatives: ``RELAX and TREX go a bit beyond `a few nips and tucks' to XML DTDs though. Technically: XML DTDs are based on 1-unambiguous tree-local grammars, while RELAX and TREX are based on tree-regular grammars. This makes them a lot more expressive and only a little more difficult to understand than DTDs; a good tradeoff'' (Joe English in comp.text.xml)