man aptitude says in part:
Unless you pass the -F option, the output of aptitude search will look something like this:
i apt - Advanced front-end for dpkg
pi apt-build - frontend to apt to build, optimize and in
cp apt-file - APT package searching utility -- command-
ihA raptor-utils - Raptor RDF Parser utilities
Each search result is listed on a separate line. The first character of each line indicates the current state of the package: the most common states are p, meaning that no trace of the package exists on the system, c, meaning that the package was deleted but its configuration files remain on the system, i, meaning that the package is installed, and v, meaning that the package is virtual. The second character indicates the stored action (if any; otherwise a blank space is displayed) to be performed on the package, with the most common actions being i, meaning that the package will be installed, d, meaning that the package will be deleted, and p, meaning that the package and its configuration files will be removed. If the third character is A, the package
was automatically installed.
For a complete list of the possible state and action flags, see the section “Accessing Package Information” in the aptitude reference guide. To customize the output of search, see the command-line options -F and --sort.