W3C home > Mailing lists > Public > www-style@w3.org > November 2007

Re: [CSS21] Case-insensitivity not defined

From: fantasai <fantasai.lists@inkedblade.net>
Date: Thu, 15 Nov 2007 18:45:26 -0500
Message-ID: <473CDA16.8050801@inkedblade.net>
CC: www-style@w3.org, 'WWW International' <www-international@w3.org>

Addison Phillips wrote:
> 
>> I find that the basic Latin letters do match each other and nothing
>> else, if you ignore the language-specific foldings, with one exception.
>> U+212A KELVIN SIGN, which looks exactly like "K" and shouldn't exist
>> anyhow (it's compatibility equivalent to a proper "K") is case-folded
>> to "k".  I consider that to come under the heading of the Right Thing.
> 
> Compatibility characters always present a problem of this sort. I think 
> this is also the Right Thing.
> 
>> It's also true that some ligatures are case-folded to their spelled out
>> equivalents:  for example, U+FB00 LATIN SMALL LIGATURE FF is case-folded
>> to simple "ff".
> 
> This is actually a Good Thing too.

It's a Good Thing for natural-language matching and search results. It is
imho not a Good Thing for defining case-insensitivity for keywords in a
computer language. Since CSS keywords are all limited to the ASCII range,
it should be possible to reliably match against CSS keywords with only
ASCII case-insensitivity. Throwing in random other characters into the mix
can cause confusion and possibly also result in security holes. I believe
the potential problems in that respect outweigh the convenience of
case-insensitivity for non-Latin user-defined identifiers.

~fantasai
Received on Thursday, 15 November 2007 23:45:46 GMT

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