Path: utzoo!attcan!uunet!cs.utexas.edu!sdd.hp.com!ucsd!nosc!logicon.com!Makey From: Makey@Logicon.COM (Jeff Makey) Newsgroups: comp.mail.uucp Subject: Re: Paths and Precedence (Re: Question about From: lines) Message-ID: <696@logicon.com> Date: 3 Jul 90 18:29:36 GMT References: <2833.2674c5b3@mccall.com> <14298@ucsd.Edu> <2836.26750678@mccall.com> <14423@ucsd.Edu> <00001FL@cdis-1.compu.com> <2999.2688d45c@mccall.com> Organization: Logicon, Inc., San Diego, California Lines: 29 In article peter@ficc.ferranti.com (Peter da Silva) writes: >In article fitz@wang.com (Tom Fitzgerald) writes: >> It's reasonable in the sense that it will make things work right, but >> unfortunately it violates RFC1123 section 5.2.16, which says that ! should >> bind tighter than %. > >OK. Sounds like RFC1123 is just plain wrong. Who wrote it, and why did >they make this choice? There is nothing wrong with RFC 1123. The relevant section (5.2.16) says: It is suggested that "%" have lower precedence than any other routing operator (e.g., "!") hidden in the local-part; for example, "a!b%c" would be interpreted as "(a!b)%c". The use of parentheses in the example is a poor attempt at using algebraic notation to describe source routing, but the part about "lower precedence" indicates to me that "a!b%c" means "deliver to "a", who should interpret "b%c" as a local-part. This is the One True Order of Precedence. RFC 1123 also makes it quite clear that only host "a" has the option of rewriting "a!b%c" as "a!c!b". :: Jeff Makey Department of Tautological Pleonasms and Superfluous Redundancies Department Disclaimer: All opinions are strictly those of the author. Internet: Makey@Logicon.COM UUCP: {nosc,ucsd}!logicon.com!Makey