[[!comment format=mdwn
 username="joey"
 subject="""comment 19"""
 date="2018-02-07T19:04:03Z"
 content="""
What if the remote wants to use some feature like NOTE, but can still
manage to work when an old git-annex does not support it? Hard bumping the
VERSION cannot support that. If the remote requires to be able to use NOTE
and sees it cannot, it can still throw an error.

There are a bunch of requests in the protocol that are optional for the
remote to support; git-annex deals with remotes that don't support them in
better ways than throwing up its hands because the special remote is too
old. It's very good that the protocol allowed adding those extensions
without bumping a version. The protocol is less extensible when it comes
replies and other messages sent by the special remote, and I want to get
the same extensibility for those.
"""]]