iff vs. if in documents

["Jesse N. Alexander" <lexiconix -at- worldnet -dot- att -dot- net>]

OK, everyone know that "iff" means "if and only iff" in a mathematical
context (theorems, postulates, etc.) But doesn't the conjunction "if" cover
or contain the restrictive "iff" condition in a document context? In other
words, in a software design document, would substituting "if" for "iff"
confound the reader? Or should all "iff"s be replaced with the phrase "if
and only if"?

I have the funny feeling that the answer is "it depends" but I had to ask.

A potential client was complaining about a writer who marked all the "iff"s
in software comments (where iff would normally be appropriate) as spelling
errors. But the couple paragraphs of the draft software description (that
were extracted from the comments in the code) seemed fine to me with the
"if"s. (Granted that the client didn't explain what the code was supposed to
do.) And since then, I have not been able to come up with a single "English"
example in which "if" is not just as good as, or better than "iff".
(Perhaps, iff is used more frequently in legal documents. Yes?)

Of course, I can find many examples in which iff is not appropriate. For
example,(with apologies to Claude McKay)a poem entitled "Iff We Must Die"
would probably have never been published! And I don't believe generations of
boys all over the world would be made to memorize a poem entitled "Iff" as a
rite of passage. (Rudyard Kipling must be spinning in his grave.)

Jesse Alexander
Lexiconix Design, Inc.
PO Box 1730
Montclair, NJ 07042
http://lexiconix.home.att.net/
mailto:lexiconix -at- worldnet -dot- att -dot- net