Re: [Idna-update] emoji and security

[Andrew Sullivan <[e-mail]>]

On Mon, Mar 12, 2018 at 06:21:25PM +0000, Michel Suignard wrote:

> I could not resist commenting on this, because unlike emoji, Egyptian
> Hieroglyphs, while looking often like colorful pictures, are the expression of
> a fully formed writing system with ideograms and phonograms and all the usual
> attributes of such a system in term of sentence structure.

Yes.  Which is why they have a general category that …

> Jokes aside, the 100s Egyptian hieroglyphs contains hundreds of semantic and
> phonetic variants and are totally unsuited for any identifier usage and are
> still fully IDN 2008 PVALID (unless of course you limit the scope using variant
> sets).

… causes them to be PVALID.  Which means they're _not_ totally
unsuited to any identifier usage, but certainly they are unsuited to
any general-purpose identifier usage and almost certainly they will
remain in at best extremely limited use effectively forever.  Emojis,
as you know perfectly well, do not have the same general category and
therefore are INVALID.

If the general-category approach to IDNA2008 was unsuitable in 2008
because it yielded examples of things that should never in principle
be identifiers, I wish someone would have made that argument.  I do
not recall it having been made, and I believe I participated pretty
avidly.  I do recall some people arguing that various archaic things
were "not needed" or "almost always unusable by anyone", but that
would have put us in the situation of going through everything one
code point at a time.  There were some who wanted to try to re-do
IDNA2003 only updated for then-current versions of Unicode, but I
think experience shows that wouldn't have worked out too well either.

Best regards,

A

-- 
Andrew Sullivan
[e-mail]