ietf-822
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Re: Fwd: I-D ACTION:draft-klyne-msghdr-registry-02.txt

2002-02-01 05:12:20

In <200201311813(_dot_)g0VIDlp28308(_at_)astro(_dot_)cs(_dot_)utk(_dot_)edu> 
Keith Moore <moore(_at_)cs(_dot_)utk(_dot_)edu> writes:

X-headers are very useful for experimental features and private agreements -
i.e. for the kinds of things where you need a new field -  but because it
isn't going to affect many people, there's no need to go through the review
process.  For similar reasons, they're okay for write-only fields even if
they are widely deployed. 

True.

IMHO X-headers for read/write fields shouldn't be used in widely deployed 
code.

True. But sadly there already exists much widely deployed code that uses them.

 If you need a new read/write header field for code that is going 
to be in widely deployed you need to get consensus on that field name
before you deploy it.

True in theory, but in the real world people do invent and deploy them
without such consensus. Indeed, this sometimes leads to poor names (such
as Mail-Copies-To which was a good idea which has been taken into Usefor,
but not the name we would have preferred).

However for a vendor that refuses to get consensus, using a X- field for a 
proprietary extension is less of a crime than using a field name that 
doesn't begin with X- for a proprietary extension.

It's a hard call, but the view on Usefor seems to be that it is more of a
crime (though for sure you could point to actual examples to illustrate
either argument). Moreover, it is not necessarily "vendors" that are to
blame.

-- 
Charles H. Lindsey ---------At Home, doing my own thing------------------------
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