Editing Uniform Resource Identifier (section)

=== Relation to XML namespaces ===

In [[XML]], a [[XML namespace|namespace]] is an abstract domain to which a collection of element and attribute names can be assigned.<!-- who or what can do such assignation? --> The namespace name is a character string which must adhere to the generic URI syntax.{{sfnp|Morrison|2006}} However, the name is generally not considered to be a URI,{{sfnp|Harold|2004}} because the URI specification bases the decision not only on lexical components, but also on their intended use. A namespace name does not necessarily imply any of the semantics of URI schemes; for example, a namespace name beginning with ''http:'' may have no connotation to the use of the [[HTTP]].

Originally, the namespace name could match the syntax of any non-empty URI reference, but the use of relative URI references was deprecated by the W3C.{{sfnp|W3C|2009}} A separate W3C specification for namespaces in XML 1.1 permits [[Internationalized Resource Identifier]] (IRI) references to serve as the basis for namespace names in addition to URI references.{{sfnp|W3C|2006}}