[whatwg] Superset encodings [Re: ISO-8859-* and the C1 control range]

[Øistein E. Andersen]

On 22 May 2008, at 12:40, Ian Hickson wrote:

> Do you have input on the EUC-JP issue?

I am now about to finish my analysis of CJK encodings (e-mail  
forthcoming), including EUC-JP.  This encoding does not seem to be  
particularly problematic, however.  Are you referring to a specific  
problem?

> On Thu, 13 Mar 2008, Øistein E. Andersen wrote:
>> Note: Similarly, IE apparently handles CS-ISO-2022-JP as distinct  
>> from
>>      ISO-2022-JP. This is something to keep in mind when looking at
>>      multi-byte encodings.
>
> What should we say about this?

The issue seems to be that IE's implementation of ISO-2022-JP is a  
large superset of what is actually specified.  (This is the case for  
several other CJK encodings as well.)  See forthcoming e-mail for an  
actual description of the extensions.

>> (TC)VN5712-2 < (TC)VN5712-1
>>
>> Opera[?] and Firefox seem to have implemented the superset only.
>
> Should we require this mapping?

For reference:
(TC)VN5712-3  <  (TC)VN5712-2 = VSCII-2 = ISO IR 180  <  (TC)VN5712-1

Only the complete set seems to be implemented (and only in Firefox),  
and MIME charset strings referring to one of the subsets do not seem  
to work at all, so no mappings are necessary.

-- 
Øistein E. Andersen