On 13/08/2016 11:13, Pete Resnick wrote: > On 11 Aug 2016, at 6:44, Stewart Bryant wrote: > >> Optional is useful in a requirements RFC. >> >> Feature x is REQUIRED >> >> Feature y is OPTIONAL > > One last (and perhaps fruitless) attempt to keep this section and > deprecate the adjectives: > > Using REQUIRED and OPTIONAL results in exactly the problem of using > passive voice anywhere: REQUIRED by whom? OPTIONAL for whom? I think that overstates the case. Certainly, they will be used as part of a passive construct, but I really can't see a problem with something like: The foobar header is OPTIONAL but the barfoo header is REQUIRED in all messages. Of course, I could construct an equivalent sentence using MAY and MUST. However, I think the adjectives are also useful in feature lists: foobar OPTIONAL barfoo REQUIRED frooba RECOMMENDED foobra OPTIONAL Brian > If you say, > "A MUST do X and B MAY do Y", it is perfectly clear which actor is > responsible (and in network protocols there are inevitably at least 2). > If you say "X is REQUIRED and Y is OPTIONAL", you'll end up needing more > text to explain the actors and their roles. > > Using REQUIRED and OPTIONAL is lazy. It makes specs less clear. They > ought to be dropped. > > pr >