XML by Example

Namespace declaration is done through attributes with the prefix xmlns fol-

lowed by the prefix. In Listing 4.6, two prefixes are declared:

qa and pa.

The attribute xmlns declares the default namespace—that is, the name-

space for those elements that have no attributes.

In summary, XML namespaces is a mechanism to unambiguously identify

who has developed which element. It’s not much but it is an essential ser-

vice.

The Namespace Name

The namespace name is the URI, not the prefix. When an XML application

compares two elements, it uses the URI, not the prefix, to recognize their

namespaces.

Therefore, in Listing 4.7 rff:name and ref:name are considered ...