> From: Peter Krebs [pkr...@gmail.com] > > Is my interpretation of the ABNF correct in this case and a SIP parser must > accept a header without a value while still checking for the "="
You are correct. This is yet another situation where the IETF has taken advantage of what it has discovered: When defining an extension mechanism, make sure that it is as general as possible. When writing RFC 3261, there was no envisioned need for a header with an empty value, but we have discovered over history, that we should not construct a grammar that excludes alternatives that are "mathematically possible" even if we cannot envision the use that they will be put to. In this case, the Allow and Accept-Language headers allow empty values... Dale _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
