The W3C XML Core Working Group has released an initial public working draft for XML 1.1, presented as a series of changes to the W3C Recommendation in Extensible Markup Language (XML) 1.0, Second Edition. Some content in this XML 1.1 working draft was previously published in the document XML Blueberry Requirements, envisioned as a limited revision of XML 1.0 to address character set issues. The decision to create a distinct XML version 1.1 rather than a new collection of errata against XML 1.0 Second Edition is grounded in the fact that "the changes affect the definition of well-formed documents." Two principal motiviations are given for the new version of XML: (1) "the Unicode Standard 2.0 on which XML 1.0 relies for character specifications has [evolved]; new characters not present in Unicode 2.0 may be used in XML 1.0 character data, but they are not allowed in XML names such as element type names, attribute names, enumerated attribute values, processing instruction targets, and so on. In addition, some characters that should have been permitted in XML names were not, due to oversights and inconsistencies in Unicode 2.0. (2) XML 1.0 discriminates against the conventions used on IBM and IBM-compatible mainframes; XML 1.0 documents generated on mainframes must either violate the local line-end conventions, or employ otherwise unnecessary translation phases before parsing and after generation."
Bibliographic information: XML 1.1. W3C Working Draft 13-December-2001. Edited by John Cowan (Reuters). Version URL: http://www.w3.org/TR/2001/WD-xml11-20011213/. Latest Version URL: http://www.w3.org/TR/xml11/.
The numbered sections in the new Working Draft correspond to those of the XML 1.0 Recommendation; sections of the Recommendation that do not appear in the new WD document remain unchanged in XML 1.1. The working group anticipates that the final edition of XML 1.1 will be composed as a complete document containing all changed and unchanged sections.
Proposed draft Section 2.13 on 'W3C Normalization Checking' contains new material: "XML processors must/should/may check whether their input documents are in W3C normalized form, as defined by [Character Model for the World Wide Web, W3C Working Draft, 28-September-2001]. XML processors must not transform the input to be in normalized form. It is a fatal error/error/not an error for the document not to be in normalized form."
Proposed draft Section 4.3.4 on 'Version Information in Entities' contains new material: "Each entity, including the document entity, can be separately declared as XML 1.0 or XML 1.1. The version declaration appearing in the document entity determines the version of the document as a whole. An XML 1.1 document may invoke XML 1.0 external entities, so that otherwise duplicated versions of external entities, particularly DTD external subsets, need not be maintained. It is an error for such entities not to be well-formed according to the rules of XML 1.0: only the line terminators and name characters of XML 1.0 are allowed... XML 1.0 documents must not invoke XML 1.1 entities... If an entity (including the document entity) is not labeled with a version number, it is treated as if labeled as version 1.0."
Principal references:
- XML 1.1. W3C Working Draft 13-December-2001.
- XML Blueberry Requirements. W3C Working Draft 21-September-2001.
- Extensible Markup Language (XML) 1.0, Second Edition
- W3C XML Core Working Group
- Mailing list for comments on XML 1.1
- Character Model for the World Wide Web