This schema defines attributes and an attribute group suitable for use by schemas wishing to allow 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 either 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 a instance element with both xml:space and xml:lang attribute In due course, we should install the relevant ISO 2- and 3-letter codes as the enumerated possible values . . .