Right now you have the "attic prune" command for automatic pruning of old revisions (kudos for a very well thought out command) as well as "attic delete".

I would like to see a "never prune" flag added to an individual archive. Maybe I have an archive that I want to keep around forever, even if pruning is applied to the attic repository. Any archive with the "never prune" flag would simply not be a candidate for pruning nor would it be included in the pruning algorithm.

I'd want to be able to specify this at two points in time:

• At the time of archive creation (attic create), maybe with an option of "--never-prune".
• At a later point in time, being able to change an existing archive to never be a candidate for pruning.

An expanded version of the concept would be "--never-prune-earlier-than DATE". Once that date has passed, the archive becomes eligible for pruning with "attic prune".