Michael I agree with Brian that priority and precedence are different. For me, priority is something that can be ordered, a number, perhaps a character or a string of characters, unbounded but where I cannot tell whether higher or lower is better without being told. Precedence is more binary, one or a group coming before another one or group. I note however that my dictionary also gives a definition of precedence as a form of priority:-) Tom Petch ----- Original Message ----- From: "Brian E Carpenter" <brian.e.carpenter@xxxxxxxxx> To: <ietf@xxxxxxxx> Sent: Tuesday, July 18, 2017 9:53 PM Subject: Re: the terms "priority" and "precedence" > On 18/07/2017 23:54, Michael Richardson wrote: > > > > We have many places in protocols where we want to express some ordering of > > pieces of information. We call these fields priority or precedence or > > Just a side note: in the design of diffserv we paid a lot of attention > to that choice of words. You might care to read section 4.2.1 of RFC2474, > which could be summarised as precedence != priority. I think there is > quite some subtlety in this area, and not so much randomness in the choices. > > Brian > > > sometimes other things. Give encode things as numbers. > > > > DNS's MX record has a "preference", in which lower numbers are better. > > BGP has a LOCAL_PREF, in which higher numbers are better. > > RAs have PreferenceLevel, in which higher numbers are better. > > ROLL has "rank", in which lower numbers mean closer to the root. > > OSPF has such numbers, which I forget at the moment. > > > > Is there any consistent usage where preference is a term used when > > higher numbers are better and priority when lower numbers are better? > > Does the RFC-editor have any suggestions? Or is it really all random. > > > > -- > > ] Never tell me the odds! | ipv6 mesh networks [ > > ] Michael Richardson, Sandelman Software Works | network architect [ > > ] mcr@xxxxxxxxxxxx http://www.sandelman.ca/ | ruby on rails [ > > > > > > > > -- > > Michael Richardson <mcr+IETF@xxxxxxxxxxxx>, Sandelman Software Works > > -= IPv6 IoT consulting =- > > > > > > >