Ron Johnson wrote: > > See RFC 2119. I think usages of may, should, must and stuff should > > follow these explanations.
Note that RFC 2119 does not mention the phrase "may not". In American english it clearly means "is not permitted". For clarity in policy documents "must not" should be used when the intent is to state that something is not permitted. If the intent is to say that one has the choice of doing or not doing something structure the sentence so as to use "may" or "optional". Don't use "may not" to mean "you can leave this out if you want to". It might be best to not use it at all as it seems to engender some confusion. Note also that the RFC says the the imperatives it defines should be used sparingly. -- John Hasler
