DocRegExt xs doc A description of a document/education-like resource. A natural-language document. Natual-language documents suitable for registration include worked-out use cases, tutorials, courses, or even material like reference cards, provided they cover Virtual Observatory techniques. A language the document is available in. Declaring support for a language does not necessarily mean a given translation is up to date or maintained. Having a complete text in a language of some previous version of a master document is enough. A URL allowing access to one or more renderings of the document. Dereferencing the URL will allow access to ready-to-use forms of the document (e.g., PDF, HTML). For documents available in multiple languages, this should typically be a "landing page" containing links to the different language versions; this could be identical to the resource's reference URL. Multiple access URLs may be given; there is no requirement that the various access URLs offer the same content. Clients are advised to consult all access URLs for the most recent and appropriate rendering of the document. A URL allowing access to an editable version of the document. The sourceURI could point to version control systems, complete files (e.g., in Open Document Format) or landing pages as with access URLs. Multiple source URLs may be given; there is no requirement that the various access URLs offer the same content. Clients are advised to consult all source URLs for the most recent and most appropriate document version.