I think that the character sets (Chinese, Cyrillic, etc.) which were supposed
to be in T.61 (1988) are part of ISO 10646 (UNIVERSAL STRING).
I asked the OSF I18N person about 10646 and here's what she told me;
any errors are due to my synopsis and feelings about having to write
my code to handle this kind of stuff. :)
The current version of ISO 10646 is basically Unicode. It is nominally
a 32bit code although there are variants and multiple conformance levels.
Right now it overlays a few distinct oriental ideograph into one
numeric code. There are many ways to encode the characters into a
byte stream, expect more to come including a seven-bit form (specifically
for email kinds of use) and a 2byte/4byte hybrid.
Also expect "thousands" of Taiwanese idographs to be added to the "UCS4"
variant as well as some other characters, too.
In short, 10646 is not the stable standard you might think it is.
/r$