2838 2006-02-11 01:42:13 +0000 RQ-126 Restricting away canonical forms (restrict-can-forms) 2008-03-08 15:03:11 +0000 1 1 1 Unclassified XML Schema Datatypes: XSD Part 2 1.1 only Other All CLOSED FIXED resolved P2 normal --- 1 cmsmcq cmsmcq www-xml-schema-comments oldest_to_newest 8203 0 cmsmcq 2006-02-11 01:42:13 +0000 This issue was originally reported by Dave Peterson. Pattern derivations remove lexical representations directly from the lexical space. If a lexical representation is not unique then it is possible with a pattern to remove the canonical representation without removing all representations, thereby leaving the value in the value space but without a canonical representation. This is related to RQ-129 (#eliminate-canonical). See (member-only link) http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2002Nov/0186.html This item was discussed in the meeting of 2003-11-21 (http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2003Nov/0050.html). Paul Biron to produce phase-1 proposal. This item was discussed, and phase-1 agreement was reached, in the meeting of 2004-03-19 (http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2004Mar/0072.html). Proposal: Dave Peterson and subsequent thread (member-only links) (http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2002Nov/0186.html) Since it's not feasible to prevent the use of patterns in such a way as to eliminate canonical representations, the only practicable resolution to this issue is to add a warning to the spec noting that this can happen and that it may in some circumstances be undesirable. Such notes have been added to section 2.1 (Datatype) and just after the definition of the pattern facet. With those notes, this requirement has been discharged.