uA namespace is declared as an attribute specification of
attribute xmlns or an attribute whose prefix is xmlns:
Example: <x xmlns:edi =
'http://ecommerce.org/schema'>
<!-- the "edi" prefix is bound to
http://ecommerce.org/schema for the "x"
element and contents -->
</x>
uA declaration applies to the element where it is
specified and to all elements within the
content of that element, unless overridden by another namespace declaration with the same attribute
name
Example: <!-- 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>