issue1096 dealt with patch version info and was closed. Also discussed there was
the specific issue that 
"the new, non-useful Ignore-this output is displayed in all darcs
versions, if they happen to pull a patch with this info. It seems that we
display all a patch's info, including new fields which might not be appropriate
for display. I think a given darcs version should predictably display only the
patch info fields it knows about.". 

Given that many users will have darcs < 2.1 for some time, I think this will be
a much bigger annoyance than people realise and I don't think darcs 2.1 should
go out without some kind of solution. Am I wrong ?

See issue1096 for related comments.

So:

1) darcs 2.1 will not produce ignore-this junk

2) however, the darcs that follows this will

3) so the fact that users will have darcs < 2.1 around for some time does not
influence our decisions about what to do, one way or the other

4) darcs 2.1 should probably learn to ignore junk from future darcs; this will
require a patch to the temporary release branch which will generate a conflict
with the current (un)stable branch

I have a pretty clear idea what to do about this and am working on it.

I'll just note my objection here.

This was resolved when bugs@darcs.net stopped receiving email:
Fri Sep 26 23:01:19 BST 2008  Eric Kow <E.Y.Kow@brighton.ac.uk>
  * Resolve issue1102: recognise but do not generate patch log 'junk'.
  
  This is a partial rollback of the two issue27 patches below.  The patches exist
  to (a) generate patch log 'junk' and (b) hide such junk from users' view.
  Because of a feature freeze, we do not want junk generation to be part of darcs
  2.1; however, we do anticipate junk-generation being part of subsequent
  versions of darcs.  To avoid users being confused by this future junk, we only
  rollback the junk-generation part, retaining the junk-hiding part.