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From: Christian.Huitema@mirsa.inria.fr (Christian Huitema)
Newsgroups: comp.protocols.iso.x400
Subject: Re: Printable format (was: Re: ISO/CCITT meeting report)
Message-ID: <9008140712.AA08564@jerry.inria.fr>
Date: 14 Aug 90 07:36:23 GMT
Lines: 34
Approved: usenet@ICS.UCI.EDU
In-Reply-To: Your message of 13 Aug 90 16:56:31 -0700.
             <9008132356.AA16616@bel.isi.edu>

Jon,

Your point is fair: going from "business card" to "user interface"
should be as straight-forward as possible. However, one should not
put too much emphasis on one given interface, i.e. the Unix command
line. In fact, as outlined by the Swedish study on user perception,
a single line expression of a set of typed tokens is always error
prone, and full screen menus are preferable. In order to easely
use the menu, one should be able to copy the content of each
field without being bothered by the escape of special characters,
etc: the choice of a delimiter outside the current X.400 set of
allowed characters, ";", is thus more adequate than a character that
needs escaping like "/". In fact, the best solution would probably
be the use of NO separator at all, and the distinction of types (C=)
from text by some typographic art, e.g. boldface of the types or
italization of the contents.

If you insist on single line expression of addresses, a la RFC-822,
you must be aware that the form <C=DE;...; S=Kaufmann;> is currently
used by some UAs. It can be directly copied from the business card,
without interpolation -- reducing the risk for errors. One may
expect that if a standard form of printing addresses is adopted,
this standard form will be supported by more UAs.

But using a text image of the X.400 addresses in a shell command is
quite another business. The set of allowed characters includes in
particular the blank and the parenthesis, and a quoting mechanism
has to be available. As long as the parameter is quoted, you can as
well include semi colons in the string! Besides, Mark Horton
assertion that the MTA is build up by a set of shell commands which
take the addresses to be reached as command line arguments is
extremely debatable...

Christian Huitema