I find it distressing that there's so much intense discussion of how
to deal with zillions of these codesets simultaneously using all
kinds of baroque header information and scheming when a wonderful
answer is lying around waiting to be picked up. Just map your codes
into something, like Unicode, that already includes the repertoire of
any other standard you'd possibly want to use. This is one of the
major wonderful features of Unicode: it includes more existing
standards and than any the competing universal set. All you need to
do is define the wrapper to put around text that's encoded that way.
I'm certainly no expert when it comes to character set issues, but I have
heard that in order to properly impliment Unicode, all implementations
need to be able to always recognize and render all incorporated character
sets. This means that applications always have to carry around a lot
of excess baggage for intances where support for the entire standard is
not required (this would account for most of the cases I would guess).
If this is true, then the implications could be significant.
Perhaps someone with a more detailed knowledge of Unicode could comment