Document Structure Description

Document Structure Description, or DSD, is a schema language for XML, that is, a language for describing valid XML documents. It's an alternative to DTD or the W3C XML Schema.

An example of DSD in its simplest form:

<dsd xmlns="http://www.brics.dk/DSD/2.0" xmlns:my="http://example.com"> <if><element name="my:foo"/> <declare> <attribute name="first"/> <attribute name="second"/> <contents> <element name="my:bar"/> </contents> </declare> </if> <if><element name="my:bar"/> <declare> <contents> </contents> </declare> </if> </dsd>

This says that element named "foo" in the XML namespace "http://example.com" may have two attributes, named "first" and "second". A "foo" element may not have any character data. It must contain one subelement, named "bar", also in the "http://example.com" namespace. A "bar" element is not allowed any attributes, character data or subelements.

One XML document that would be valid according to the above DSD would be:

<foo xmlns="http://example.com" second="2"> <bar/> </foo>