... and the only conformant applications are those which pass PUA characters through untouchted, though they would generally do so with a source and/or sink that assigns meaning and hence the system as a whole is still non-conformant.Not if the source and the sink are consenting adults, or children, or processes, which can assign meaning to PUA characters by private agreement. The source and the sink are higher level entities with their own higher level protocols. The channel between source and sink, which is the Unicode level and below, should be transparent to PUA characters, indeed to all characters apart from defined transformations. That surely is the point of the PUA. If the channel starts messing around with the characters sent through it, that is what is non-conformant.
If the higher level protocol chooses not to use PUA characters, it is of course entitled not to, and in that case to treat as a protocol error any PUA characters it receives from a lower layer.
-- Peter Kirk [EMAIL PROTECTED] (personal) [EMAIL PROTECTED] (work) http://www.qaya.org/
