Mark Crispin wrote (in the 822 list, regarding a MIME problem):
As an example, consider that years after the bug in an ancient version of
BSD was fixed, we still have to worry about handling MAIL FROM commands in
SMTP that are missing the host name, or that have colon delimiters in the at-
domain-list instead of commas. This isn't documented in SMTP; rather, it's
in the folklore of how you get your SMTP server to be interoperable...
A procedural thought on this: it Sure Would Be Nice if some of the people
who have been exposed to things like this sat down and wrote a few
Informational RFCs *documenting* some of this folklore. One of the most
infuriating things about implementing some of the Internet protocols is
running across these bits of important information that aren't written
down *anywhere*, apparently on the assumption that anyone who needs to
know them already does. Not so.
While there is no substitute for interoperability testing, such testing
should be significantly quicker and less painful if people didn't have
to rediscover problems that others have known about for years (but have
never bothered to write down).
Henry Spencer at U of Toronto Zoology
henry(_at_)zoo(_dot_)toronto(_dot_)edu utzoo!henry