S.Kille@CS.UCL.AC.UK (Steve Kille) (07/14/89)
Let me give some history on this issue. In the original RFC 987, all the attributes were treated as a set. It was realised that this was a problem for repeated attributes (Org Units and Domain Defined). A solution was agreed and published in RFC 1026. It was decided to require an ordering (as opposed to labelling OU1, OU2 etc). The chosen order was most significant on the RHS. This was picked to align with the general hierarchy of RFC 822 addresses, which have a right to left flow. This is of most relevance when there is a mix of LHS and RHS encoding. In the interim, RARE WG1 have defined a human format of addresses, which uses the reverse order (they were clearly informed that this was the opposite choice to RFC 987). This was done for reasons of naturalness. Because some users will be used to the non-987 order, they may generate attributes in the wrong order. For this reason, it is suggested that gateways apply a heuristic (on the assumption that attributes will be entred in a consistent order). This was agreed at the meeting. The issue in question is what order should the gateway generate in. View 1 (Huitema + Craigie). The gateway should be allowed to generate attributes in any order. This would allow them to use their respective preferred orders (most significant on the left, and most signficant in the middle). Gateway output could then be aligned with user expectation. View 2 (Kille) Consistency between gateways is very important. (RFC 822) Users should expect to see the same form of X.400 address from different gateways. Message IDs should always be generated in the same way. Therefore, this specification should require an order when generating addresses. If an order is required, the specification should follow the choice made in 987/1026. There is no reason to do anything different. Making the addressing incompatible with 987 would be a disaster. ----- The three people referenced had very strong views, and dominated the discussion. However, I detected support for both views among the remainder. Stef kept us off each others throats! As editor/author, I've chosen to go the way I want. I'd appreciate comments on this. Please read the text, and don't just base discussion on this message. I have a very strong feeling of deja vu here. 8 years ago, the UK and US picked opposite domain orders, each arguing "naturalness" as the reason for choice. It doesn't really matter that much. However, having a mixture is an absolute disaster. I fear that we are about to relive our history. Steve