Hiya, I noted only one issue that might need fixing: - If two entities are using this scheme and have an agreed set of rules, don't you need to say that packets that don't match any rule(s) should be sent unmodified? I also noticed a couple of nits: - Intro: "There is no risk to lock a device in a particular version of CoAP." I'm not fully sure what that's trying to say but a) "no risk" is a major claim that's not justified:-) and b) SCHC (by design) does inherently risk being less effective if protocols or patterns of protocol usage change. I'd say just delete the sentence. - section 2: "SCHC C/D" is used without being defined. - 7.2: Typo: "The Inner Plaintext contains sensible information which is not necessary for proxy operation." s/sensible/sensitive/ I guess.