W3C issues' exclusive Canonical XML' as a Recommendation. (Internet Products).
A W3C Recommendation indicates that a specification is stable, contributes to Web interoperability, and has been reviewed by the W3C Membership, who are in favor of supporting its adoption by academic, industry, and research communities.
Exclusive XML Canonicalization Makes XML Signatures Work with Complex Applications, Web Services Digital signatures provide integrity, signature assurance and non-repudiatability over Web data. Such features are especially important for documents that represent commitments such as contracts, price lists, and manifests.
XML Signatures have the potential to provide reliable XML-based signature technology, and are considered a mandatory component of many models for Web Services. However, various processors may introduce incidental changes into a document over the course of its processing. The process of canonicalization removes these incidental changes. Additionally, in some cases, particularly for signed XML in protocol applications (that is, ones that use SOAP 1.2, HTTP/l.1, or others) there is a need to canonicalize a subdocument in such a way that it is substantially independent of its XML context.