Date: Fri, 5 Jan 1996 05:04:47 +0100 (MET)
From: Jacob Palme <jpalme@dsv.su.se>
To: ietf-drums <drums@cs.utk.edu>
Subject: The conservative and liberal commandment
Message-ID: <Pine.SUN.3.91.960105045713.28505A-100000@ester.dsv.su.se>
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"Be liberal in what you accept and conservative in what you produce."

The problem with this commandment is that it does not specify what
is "liberal" and "conservative". What the statement says, is
actually that there are two different standards, one standard
for what you should produce and one standard for what you should
accept. But IETF standards usually do not explicitly say what
is in these two standards. The knowledge is a kind of folklore,
which is "known" by developers but not written down.

I think this is wrong. The standards should clarify what you
should accept and not accept and what you should produce and
not produce. I.e. the standards should be allowed to specify
two alternatives, one for what you produce and one for what
you accept.

Examples:

Line length: Acccept 1000 character lines, but never send
more than 80 character lines.

Quoting: Accept quoting in header fields, but never send
out anything quoted except when you have to because you
are repeating someone elses e-mail address which has quotes
in it. Never allow your local users and mailing lists to
have quoted characters.

Spaces: Since quoting is not allowed in what you produce,
and since spaces must be quoted, a consequence is that
spaces are not to be produced in addresses.

Re-writing of spaces: Replace spaces with ".", not with
"_" or some other funny character.

Loop control: Never send automatic messages to user whose
name contains the substring "daemon" in upper or lower case.

etc. etc.

------------------------------------------------------------------------
Jacob Palme <jpalme@dsv.su.se> (Stockholm University and KTH)
for more info see URL: http://www.dsv.su.se/~jpalme