On 08Feb18, John R. Levine allegedly wrote: > On Thu, 8 Feb 2018, Mark Delany wrote: > > Heh. I'm still waiting to hear a good reason as to why "v=" exists at all - > > apart > > from exposing brittle parsers which mistakenly expect it to show up as the > > first > > tag. > > I had a draft that invented v=2, for headers with a tag syntax that is not > quite backward compatible with the current spec. I realize that we could > change the header to DKIM-Improved-Signature but the change was small and > it smelled to me like the same header.
Yes, one can certainly contrive a situation in which they prefer a v=2 solution, but as you say, the requirement can be just as easily satisfied in a number of other ways too. A new header is one as is the presence of a new tag and v= is a third. There are other ways as well. Given we're talking about standards, it's de rigueur that we end up with at least three competing ways of achieving the same outcome without any guidance whatsoever as to which mechanism to choose when and why. Underlying all this of course is the assumption that programmers intuit the possibility of change inherent in these non-essential mechanisms and code and test accordingly. Now that's a goodun. Mark. _______________________________________________ NOTE WELL: This list operates according to http://mipassoc.org/dkim/ietf-list-rules.html