(was Re: I'm struggling with 2219 language again) >> Where you want to use MUST is where an implementation might be tempted >> to take a short cut -- to the detriment of the Internet -- but could >> do so without actually breaking interoperability. A good example is >> with retransmissions and exponential backoff. You can implement those >> incorrectly (or not at all), and still get "interoperability". I.e., >> two machines can talk to each other. Maybe you don't get "good" >> intereoperability and maybe not great performance under some >> conditions, but you can still build an interoperabile implementation. >> IMO, too many specs seriously overuse/misuse 2119 language, to the >> detriment of readability, common sense, and reserving the terms to >> bring attention to those cases where it really is important to >> highlight an important point that may not be obvious to a casual >> reader/implementor. >Sadly true. We can fix that, by discussing it further, or as Scott mentioned the survey [*] >> two machines can talk to each other. Maybe you don't get "good" >> intereoperability and maybe not great performance under some >> conditions, but you can still build an interoperabile implementation. As machines reads and writes may depend on conditions, I don't think it is true that you can still interoperabile implementation by ignoring using/documenting requirement keys language (i.e. all common keys of all languages). AB