Re: [idn] case folding

[Harald Tveit Alvestrand <Harald@Alvestrand.no>]

At 16:25 12.06.2000 +0800, James Seng wrote:
>If we were to discuss this and since we will be basing it on Unicode, it would
>be less confusion if people can refer the glyphs to be allowed or disallowed
>using Unicode Categories.
>
>Abbr  Description                    Proposal
>Lu    Letter, Uppercase              Allow
>Ll    Letter, Lowercase              Allow
>Lt    Letter, Titlecase              Allow
>Mn    Mark, Non-Spacing              Disallow
>Mc    Mark, Spacing Combining        Disallow
>Me    Mark, Enclosing                Disallow
.....

Agree about the style of attack. Those categorizations can be found in the 
Unicode code tables (column 3).

However, looking back at the requirement document's architectural chapter 
(chapter 1.4), I feel strongly that we should say:

- The DNS service layer (the packet formats that go on the wire)
   MUST NOT limit the codepoints that can be used.
   This interface SHOULD NOT assign meaning to name strings.
- The application service layer, where "gethostbyname" and friends reside,
   MAY constrain the name strings to be used in certain services.

The difference is important.

                  Harald


--
Harald Tveit Alvestrand, EDB Maxware, Norway
Harald.Alvestrand@edb.maxware.no