Dear Maintainer,

It would be very helpful to add to the debmirror man page an explanation
on how to mirror a single distribution without disturbing the other
distributions. For example, if I am using debmirror to mirror sid,
testing, bullseye, and buster and my buster mirror is damaged I want to
re-sync buster without having to re-sync everything else.

I use the --nocleanup option to do this but it took me some time to figure
this out. So I suggest adding to the man page explaining how --nocleanup
can be used to do this.