On the [/cgi-bin/mailman/listinfo/tahoe-dev tahoe-dev mailing list], Zooko suggests:

  I really like using the mailing list for patches, because the mailing
  list is a public, on-the-record conversation that includes everyone.

  What about this:

{{{
  darcs send -o patch.darcspatch
  darcs diff -u -p"${PATCHRE}" > patch.diff.txt
}}}

  and then send both to the mailing list as attachments?  This is more
  work for the submitter, as they have to attach the files to a message
  and send the message (instead of allowing "darcs send" to send the
  message for them).

  The good things about this are:
  * hopefully everyone can see the patch contents in-line in the mail, and
  * you can add a "cover letter" -- a message to the mailing list about the patch.