Last Tuesday I sent this to the list: http://www.imc.org/idn/mail-archive/msg05544.html
The stringprep draft contains this text at the end of section 4: "A profile MUST refer to a specific version of [UAX15]. If a later version of [UAX15] changes the algorithm used for normalization, that later version MUST NOT be used with the same version of the profile." Followed by this unanswered question: "Patrik asks: Is not addition of unassigned codepoints regarded an update of UAX15? This is relevant here." I've yet to see a response to my original query. Assuming that assigning codepoints that were previously unassigned would require an update to Unicode 3.1.0, and UAX15 very clearly lists the normative Unicode version as 3.1.0, perhaps the answer to Patrik's question is "yes" -- UAX15 would need to be updated (though the normalization algorithm itself might not change), but as described in UAX15 backward compatibility would have to be preserved. Would it make sense to add something like this to the end of section 4 (perhaps prior to the "A profile MUST" sentence) to answer Patrik's question: "The composition process described in [UAX15] requires a fixed composition version of Unicode to ensure that strings normalized under one version of Unicode remain normalized under all future versions of Unicode." If I've missed the mark I'll apologize in advance. No matter what, though, Patrik's question needs to be removed from the draft and either text should be added to answer the question or someone should explain why the question is irrelevant. -Scott-
