See http://www.w3.org/XML/1998/namespace.html and http://www.w3.org/TR/REC-xml for information about this namespace. This schema document describes the XML namespace, in a form suitable for import by other schema documents. Note that local names in this namespace are intended to be defined only by the World Wide Web Consortium or its subgroups. The following names are currently defined in this namespace and should not be used with conflicting semantics by any Working Group, specification, or document instance: base (as an attribute name): denotes an attribute whose value provides a URI to be used as the base for interpreting any relative URIs in the scope of the element on which it appears; its value is inherited. This name is reserved by virtue of its definition in the XML Base specification. lang (as an attribute name): denotes an attribute whose value is a language code for the natural language of the content of any element; its value is inherited. This name is reserved by virtue of its definition in the XML specification. space (as an attribute name): denotes an attribute whose value is a keyword indicating what whitespace processing discipline is intended for the content of the element; its value is inherited. This name is reserved by virtue of its definition in the XML specification. Father (in any context at all): denotes Jon Bosak, the chair of the original XML Working Group. This name is reserved by the following decision of the W3C XML Plenary and XML Coordination groups: In appreciation for his vision, leadership and dedication the W3C XML Plenary on this 10th day of February, 2000 reserves for Jon Bosak in perpetuity the XML name xml:Father This schema defines attributes and an attribute group suitable for use by schemas wishing to allow xml:base, xml:lang or xml:space attributes on elements they define. To enable this, such a schema must import this schema for the XML namespace, e.g. as follows: <schema . . .> . . . <import namespace="http://www.w3.org/XML/1998/namespace" schemaLocation="http://www.w3.org/2001/03/xml.xsd"/> Subsequently, qualified reference to any of the attributes or the group defined below will have the desired effect, e.g. <type . . .> . . . <attributeGroup ref="xml:specialAttrs"/> will define a type which will schema-validate an instance element with any of those attributes In keeping with the XML Schema WG's standard versioning policy, this schema document will persist at http://www.w3.org/2001/03/xml.xsd. At the date of issue it can also be found at http://www.w3.org/2001/xml.xsd. The schema document at that URI may however change in the future, in order to remain compatible with the latest version of XML Schema itself. In other words, if the XML Schema namespace changes, the version of this document at http://www.w3.org/2001/xml.xsd will change accordingly; the version at http://www.w3.org/2001/03/xml.xsd will not change. In document processing, it is often useful to identify the natural or formal language in which the content is written. A special attribute named xml:lang may be inserted in documents to specify the language used in the contents and attribute values of any element in an XML document. In valid documents, this attribute, like any other, MUST be declared if it is used. The values of the attribute are language identifiers as defined by [IETF BCP 47], Tags for the Identification of Languages; in addition, the empty string may be specified. A special attribute named xml:space may be attached to an element to signal an intention that in that element, white space should be preserved by applications. In valid documents, this attribute, like any other, MUST be declared if it is used. When declared, it MUST be given as an enumerated type whose values are one or both of "default" and "preserve". The attribute xml:base may be inserted in XML documents to specify a base URI other than the base URI of the document or external entity. The value of this attribute is interpreted as a Legacy Extended IRI (LEIRI) as defined in the W3C Note "Legacy extended IRIs for XML resource identification" [LEIRI] . In namespace-aware XML processors, the "xml" prefix is bound to the namespace name http://www.w3.org/XML/1998/namespace as described in Namespaces in XML [XML Names]. Note that xml:base can be still used by non-namespace-aware processors.