Re: 8 bit characters in DNS names (and URNs?)

Keld J|rn Simonsen (
Thu, 7 Mar 1996 07:43:45 +0100

Message-Id: <>
From: (Keld J|rn Simonsen)
Date: Thu, 7 Mar 1996 07:43:45 +0100
In-Reply-To: Larry Masinter <>
To: Larry Masinter <>
Subject: Re: 8 bit characters in DNS names (and URNs?)

Larry Masinter writes:

> While in ASCII you can define 'case independent match' by
> performing 'translate to upper case and then use string equality',
> this does not work for other character repertoires, e.g., JIS might
> have separate codes for single and double-wide codes yet want to treat
> them equivalent for matching.
> While uppercase mapping is culturally sensitive, can we not make a
> culturally independent 'character matching' algorithm that is good
> enough for directory services. Perhaps it means treating accented and
> unaccented versions of French initial capitals equivalent, even though
> this equivalence is not determined by 'canonicalization'?
ISO/IEC JTC1/SC22/WG20 is producing a sorting/comparison standard
that may be used for this purpose. It has a number of levels that
the comparison may be done at, for exmaple level 1 would equivalence
all "A"s and the level could also equivalence single and double-
width encodings (of the latin letters, mostly). The standard is
ISO 14651 now appearing as WD3 and going to CD stage in May 1996.