1. I have a copy of the 1984 X.208 which (in table 6, page 44) lists
the T61 String registration numbers as 87, 102, 103, 106, 107 SPACE
and DELETE. Does anyone have a 1988 or 1992 version of X.208 ? Are
there changes to this list ?
2. Does anyone have a mapping from the ISO IR numbers (87, 102,...) to
the pertinent ISO standards (ISO 646 ?, ISO 6937 ?, ISO 8859 ?) ?? ???
87 isn't an ISO standard, it's Japan's JIS X 0208-1983 (called JIS C
6226-1983 at the time of registration).
102, 103, 106 and 107 are T.61's primary graphic, supplementary
graphic, primary control and supplementary control character sets,
respectively. I don't know if T.61 also has an ISO number.
3. Is anyone working on (...is there a need for...) implementor's
agreements for the use of T.61 String in PEM certificates and MIME
messages ? This is an area of great ambiguity IMHO. E.g. Do ESC
sequences that change character sets apply to whole distinguished
names or just to the AVA in which they appear ? Can I change a
character set in the middle of an AVA (mail message, whatever) ?
I haven't the foggiest what you mean by "distinguished names" and
"AVA", but, as far as MIME is concerned, in order to use T.61 in,
e.g., plain text, you need to register such a "charset" with the IANA
(unless you use the "X-" experimental feature).
I'm not at all familiar with T.61 itself, but it sounds like the ESC
sequences are rather similar to ISO 2022's (perhaps they are a subset
of 2022). Since ESC sequences can be used in many different ways to
mean the same thing, people have in the past chosen suitable subsets
of 2022 to keep it simple. This paves the way for interoperability,
since everybody implements the same, simple set. A good example (only
example?! :-) of this is Japan's JUNET specification.
So, "changing a character set in the middle" may be allowed, depending
on the particular specification. Is there any established usage of
T.61 that you have in mind (or want to be compatible with)?
4. Is there anyone that has a good grasp of all of the relevant issues
surrounding T.61 ? Should I wait for ISO 10646 and Unicode ?
I don't know. That depends on your "customers". If you want to get
people to use your email system in Japan, for example, 10646 and
Unicode are currently less important than the JUNET specification.
Hope this helps a little,
Erik M. van der Poel
Software Research Associates, Inc., Tokyo, Japan TEL +81-3-3234-2692