Canonical XML specifies a standard serialization of XML that, when applied to a subdocument, includes the subdocument's ancestor context including all of the namespace declarations and attributes in the "xml:&qout; namespace. However, some applications require a method which, to the extent practical, excludes ancestor context from a canonicalized subdocument. For example, one might require a digital signature over an XML payload (subdocument) in an XML message that will not break when that subdocument is removed from its original message and/or inserted into a different context. This requirement is satisfied by Exclusive XML Canonicalization.