text: 2004-02-04 Namespaces in XML 1.1 Bray Tim Hollander Dave Layman Andrew Tobin Richard XML namespace An XML namespace is identified by an IRI reference; element and attribute names may be placed in an XML namespace using the mechanisms described in this specification. expanded name An expanded name is a pair consisting of a namespace name and a local name. namespace name For a name N in a namespace identified by an IRI I, the namespace name is I. For a name N that is not in a namespace, the namespace name has no value. local name In either case the local name is N. qualified name A qualified name is a name subject to namespace interpretation. identical The two IRIs are treated as strings, and they are identical if and only if the strings are identical, that is, if they are the same sequence of characters. declared A namespace (or more precisely, a namespace binding) is declared using a family of reserved attributes. Such an attribute's name must either be xmlns or begin xmlns:. These attributes, like any other XML attributes, may be provided directly or by default. namespace prefix If the attribute name matches PrefixedAttName, then the NCName gives the namespace prefix, used to associate element and attribute names with the namespace name in the attribute value in the scope of the element to which the declaration is attached. default namespace If the attribute name matches DefaultAttName, then the namespace name in the attribute value is that of the default namespace in the scope of the element to which the declaration is attached. local part The LocalPart provides the local part of the qualified name. namespace-well-formed A document is namespace-well-formed if it conforms to this specification. namespace-valid. namespace-validating A validating XML processor that conforms to this specification is namespace-validating if in addition it reports violations of namespace validity. additional characters The additional characters allowed in IRIs by are: IRI reference An IRI reference is a string that can be converted to a URI reference by applying the following steps: