Why is cp1252 special?

[Torsten Bronger]

Hallöchen!

I use recent CVS versions of Gnus and Emacs.

After a couple of non-declared encodings in Outlook postings which I
received with Gnus, I wanted to change the fallback chain from cp437
(I've got a lot of old MSDOS files) to cp1252.  At the moment, my
.emacs contains

(define-coding-system-alias 'cp1252 'windows-1252)
(prefer-coding-system 'cp1252)
(prefer-coding-system 'iso-latin-1)
(prefer-coding-system 'utf-8)

I'm just curious: Why is there some sort of asymmetry between cp1252
and most (if not all) other codepages?  In particular, why is the
first line above necessary?  By contrast, I can say

(prefer-coding-system 'cp1257)

without problems.  A usenet search yielded some information about
the fact that cp1252 *is* special but not why.  Additionally,
news:v9smnfv8ib.fsf@marauder.physik.uni-ulm.de suggests that new
Emacs versions should allow

(codepage-setup 1252)

however, this doesn't work for me in .emacs.

Tschö,
Torsten.

-- 
Torsten Bronger, aquisgrana, europa vetus            ICQ 264-296-646