The top half of the screen shows a list of packages. For each package you see
four columns for its current status on the system and mark. In terse mode (use
`v' to toggle verbose display) these are single characters, from left to right:
Error flag: Space - no error (but package may be in broken state - see below)
`R' - serious error during installation, needs reinstallation;
Installed state: Space - not installed;
`*' - installed;
`-' - not installed but config files remain;
packages in these { `U' - unpacked but not yet configured;
states are not { `C' - half-configured (an error happened);
(quite) properly { `I' - half-installed (an error happened);
installed { `W',`t' - triggers are awaited resp. pending.
Old mark: what was requested for this package before presenting this list;
Mark: what is requested for this package:
`*': marked for installation or upgrade;
`-': marked for removal, but any configuration files will remain;
`=': on hold: package will not be processed at all;
`_': marked for purge completely - even remove configuration;
`n': package is new and has yet to be marked for install/remove/&c.
Also displayed are each package's Priority, Section, name, installed and
available version numbers (shift-V to display/hide) and summary description.