-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 08/30/2011 09:11 AM, Keith Moore wrote: > On Aug 30, 2011, at 12:06 PM, Marc Petit-Huguenin wrote: > >> The meaning of SHOULD is clear for the authors (it "mean[s] that there may exist >> valid reasons in particular circumstances to ignore a particular item, but the >> full implications must be understood and carefully weighed before choosing a >> different course."), the problem is that some implementers use a different >> meaning (I do not have to implement this if it is inconvenient or difficult for >> me to implement), vendors another one (SHOULD gave us the right to not implement >> it). I even read somewhere, perhaps on this list, about a vendor that rejected >> any bug report against a SHOULD. Conditional MUST, in my opinion, does not have >> this problem. > > But conditional MUST has other problems, namely that you have to enumerate the > exceptions for the MUST, and that's not always practical. > > Implementors who think that SHOULD gives them a free pass to avoid implementing > something that's needed to interoperate are misreading 2119. But document > editors should avoid using SHOULD for cases where failure to implement the > requirement will result in interoperability failure. > > I could see maybe posting an erratum or a brief update to 2119, but I think that > reopening that document in general is a Very bad Idea. And for existing > documents that misuse SHOULD, the appropriate thing to do is to update those > documents or post errata to those documents, rather than try to retroactively > change the meaning of the keywords in those documents. I like your definition a previous email, so perhaps an alternative solution to updating 2119 is for authors who really care about this subject is to integrate it in the Terminology section, something like this: 2. Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. "SHOULD", "SHOULD NOT", "RECOMMENDED", and "NOT RECOMMENDED" are appropriate when valid exceptions to a general requirement are known to exist or appear to exist, and it is infeasible or impractical to enumerate all of them. However, they should not be interpreted as permitting implementors to fail to implement the general requirement when such failure would result in interoperability failure. - -- Marc Petit-Huguenin Personal email: marc@xxxxxxxxxxxxxxxxxx Professional email: petithug@xxxxxxx Blog: http://blog.marc.petit-huguenin.org -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iEYEARECAAYFAk5dDYkACgkQ9RoMZyVa61fA6gCfYTawSM53Uy7okAgidhSyQZzH 8JUAn3AwH0wz96A9K2EfyALIsVkjAFJP =L35E -----END PGP SIGNATURE----- _______________________________________________ Ietf mailing list Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf