Parameters for top-level XML media types?

[MURATA Makoto <murata@xxxxxxxxxxxxxxxxxxxxxxxxx>]

We have agreed on two points about fallback.

> 	3. Fallback to general-purpose XML applications is not useful.
> 
> 	4. Document-like XML documents can be handled by general-purpose 
> 	   XML viewers

Other than fallback, are there any reasons for introducing top-level 
XML media types?  One possible reason is that all subtypes can 
share parameters of the top-level media types.  Possibilities for 
such parameters are as below:

- the version of XML,

- the version of Unicode,

- how the Private Use Area (PUA) of Unicode is used 
	[Rick Jelliffe wrote: "This also could have bearing on the PUA 
	(private use area) character problem, and the problem of corporate 
	character sets (e.g. Hong Kong's GCCS)."]

- which conversion table (Note: for a given CCS, more than one conversion 
  table may exist),

- which schema language is used (DTD or the upcoming schema language from W3C),

- which stylesheet (XSL, CSS, DSSSL, etc.) is used, and

- other issues mentioned in my mail "List of issues".

Does anybody think that some of them are good enough reasons for introducing 
top-level XML media types?  (I am just asking.)

Cheers,



Makoto
 
Fuji Xerox Information Systems
 
Tel: +81-44-812-7230   Fax: +81-44-812-7231
E-mail: murata@xxxxxxxxxxxxxxxxxxxxxxxxx