Debian Aptitude Search

The Results

If you've used Debian aptitude to search for packages, you'll have seen the character entries that are returned along with your search results.

Something like:

# aptitude search emacs
p   acl2-emacs  - A Computational Logic
i   emacs       - The GNU Emacs editor (metapackage)
id  emacs-chess - a client for playing Chess
i A emacs23     - The GNU Emacs editor (with GTK+)
p   emacs23-el  - GNU Emacs LISP (.el) files
v A emacs23-gtk -
ppA emacs23-nox - The GNU Emacs editor (without X)
v   emacsen     -

What do the characters mean?

The first character of each line indicates the current state of the package. The most common states are:

p no trace of the package exists on the system
c the package was deleted its config files remain 
i the package is installed
v the package is virtual

The second character indicates the stored action to be performed on the package. The most common actions are:

i  the package will be installed
d the package will be deleted, and 
p the package and config files will be removed
[Blank space] no action to be performed

The third character if shown, indicates:

A the package was automatically installed

Hope this helps interpret your search results.