Undeclaring prefixes

• xmlns:prefix="" is now legal

• Important in applications such as XSLT and W3C XML Schema Language that use prefixes in attribute values and element content

• Example from the spec:

  <?xml version="1.1"?>
  <x xmlns:n1="http://www.w3.org">
      <n1:a/>               <!-- legal; the prefix n1 is bound to http://www.w3.org -->
      <x xmlns:n1="">
          <n1:a/>           <!-- illegal; the prefix n1 is not bound here -->
  	<x xmlns:n1="http://www.w3.org">
              <n1:a/>       <!-- legal; the prefix n1 is bound again -->
          </x>
      </x>
  </x>