Namespace URIs do not necessarily point to a document, page, or schema

• Purely formal

• Can point somewhere but do not have to

• Parsers compare namespace URIs on a character by character basis. These are three different namespaces:

  • http://www.w3.org/1999/XSL/Transform

  • http://www.w3.org/1999/XSL/Transform/

  • http://www.w3.org/1999/XSL/Transform/index.html