Prohibiting mapping of PVALID characters

Paul Hoffman phoffman at
Thu Dec 10 01:48:03 CET 2009

At 3:25 PM -0800 12/9/09, Kenneth Whistler wrote:
> > At 2:26 PM -0800 12/9/09, Kenneth Whistler wrote:
>> >The other problem with this is that it might cause implementers'
>> >heads to explode when they realize that normalization to NFC
>> >is required (MUST)
>> Uh, oh. Where did you get that idea?
>Protocol, 5.2:
>5.2. Conversion to Unicode
>The string is converted from the local character set into
>Unicode, if it is not already in Unicode. Depending on local
>needs, this conversion may involve mapping some characters
>into other characters as well as coding conversions...
>The results MUST be a Unicode string in NFC form.
>Strings don't magically get to be "in NFC form", without
>being mapped (via normalization algorithm) from whatever form
>they started out as, *into* NFC form.

In this case, yes they do. That "MUST" is probably wrong; I believe that the statement is meant to say "The results will be a Unicode string in NFC form".

John, et. al.: is my understanding correct here?

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