Table of contents

Appendices

6.1 Namespace Scoping

chg The scope of a namespace declaration declaring a prefix extends from the beginning of the start-tag in which it appears to the end of the corresponding end-tag, excluding the scope of any inner declarations with the same NSAttName part. In the case of an empty tag, the scope is the tag itself.

chg Such a namespace declaration applies to all element and attribute names within its scope whose prefix matches that specified in the declaration.

add The [expanded name] corresponding to a prefixed element or attribute name has the IRI to which the [prefix] is bound as its [namespace name] , and the [local part] as its [local name] .

<?xml version="1.1"?>

<html:html xmlns:html='http://www.w3.org/1999/xhtml'>

  <html:head><html:title>Frobnostication</html:title></html:head>
  <html:body><html:p>Moved to 
    <html:a href='http://frob.example.com'>here.</html:a></html:p></html:body>
</html:html>

Multiple namespace prefixes can be declared as attributes of a single element, as shown in this example:

<?xml version="1.1"?>
<!-- both namespace prefixes are available throughout -->
<bk:book xmlns:bk='urn:loc.gov:books'
         xmlns:isbn='urn:ISBN:0-395-36341-6'>
    <bk:title>Cheaper by the Dozen</bk:title>
    <isbn:number>1568491379</isbn:number>
</bk:book>

add The attribute value in a namespace declaration for a prefix MAY be empty. This has the effect, within the scope of the declaration, of removing any association of the prefix with a namespace name. Further declarations MAY re-declare the prefix again:

<?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>