On Sep 1, 2011, at 2:58 AM, Hector wrote: > 6. Guidance in the use of these Imperatives > > Imperatives of the type defined in this memo must be used with care > and sparingly. In particular, they MUST only be used where it is > actually required for interoperation or to limit behavior which has > potential for causing harm (e.g., limiting retransmisssions) For > example, they must not be used to try to impose a particular method > on implementors where the method is not required for > interoperability. > > That last sentence is so clear. Maybe the error is not using an uppercase MUST NOT and NOT REQUIRED in that last sentence. Maybe software people need logic statements like: I actually think that the last sentence is overbroad. There are other defensible reasons to use the 2119 keywords than those enumerated in the document. And those words can be (and have been) interpreted in such a way as to compel working groups to fail to make design choices, and to permit too many alternative choices in implementations. Keith _______________________________________________ Ietf mailing list Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf