At 9:56 AM -0800 2/1/02, Yves Arrouye wrote: >The interesting scenario is: Server S is on Nameprep-08 (where a deletion >mapping has been introduced for codepoint U+XXXXX), Client A is on >Nameprep-07 but his OS supports Unicode 4.0 and its IME generates U+XXXXX. >Client A will then pas U+XXXXX unchanged (since it was unassigned when >Nameprep-07's tables were generated) and Server S won't find a match, since >its stored strings do not have U+XXXXX.
That scenario will happen, and it is *supposed* to happen. It is identical to if Nameprep-08 mapped U+XXXX to U+XYZX. The client must not get a positive response to a query that includes characters that are not allowed in the version on the authoritative server. > Same for case mapping, if that were >to happen. The user has no clue what is happening to her. Correct. It is identical to a user accidentally entering a Greek capital Alpha instead of a Latin capital A. Or, even if we didn't do IDN, the user accidentally enters numeral 0 instead of Latin capital O. The DNS matching scheme will simply say "no match". In other words, these failure scenarios are not a criticism of the versioning method, they are a criticism of the simple matching in DNS. --Paul Hoffman, Director --Internet Mail Consortium
