Occurrences

Acronym Expansion

Namespaces in XML

Description

A single XML document may contain elements and attributes that are defined for and used by multiple software modules. If such a markup vocabulary exists which is well-understood and for which there is useful software available, it is better to re-use this markup rather than re-invent it. Such documents, containing multiple markup vocabularies, pose problems of recognition and collision. Software modules need to be able to recognize the tags and attributes which they are designed to process, even in the face of"collisions" occurring when markup intended for some other software package uses the same element type or attribute name. These considerations require that document constructs should have universal names, whose scope extends beyond their containing document. The XML namespaces mechanism accomplishes this.An XML namespace is a collection of names, identified by a URI reference (RFC2396), which are used in XML documents as element types and attribute names. XML namespaces differ from the"namespaces" conventionally used in computing disciplines in that the XML version has internal structure and is not, mathematically speaking, a set. These issues are discussed in"A. The Internal Structure of XML Namespaces".

W3C specification

http://www.w3.org/TR/REC-xml-names/