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.
