-
- <varlistentry><term><option>upgrade</option></term>
- <listitem><para><literal>upgrade</literal> is used to install the
- newest versions of all packages currently installed on the system
- from the sources enumerated in
- <filename>/etc/apt/sources.list</filename>. New package will be
- installed, but existing package will never removed.
+
+ <varlistentry><term><option>install</option>, <option>remove</option>, <option>purge</option> (&apt-get;)</term>
+ <listitem><para>Performs the requested action on one or more packages
+ specified via ®ex;, &glob; or exact match. The requested action
+ can be overridden for specific packages by append a plus (+) to the
+ package name to install this package or a minus (-) to remove it.
+ </para><para>
+ A specific version of a package can be selected for installation by
+ following the package name with an equals (=) and the version of the
+ package to select. Alternatively the version from a specific release can be
+ selected by following the package name with a forward slash (/) and
+ codename (&debian-stable-codename;, &debian-testing-codename;, sid …) or suite name (stable,
+ testing, unstable). This will also select versions from this release
+ for dependencies of this package if needed to satisfy the request.
+ </para><para>
+ Removing a package removes all packaged data, but leaves usually
+ small (modified) user configuration files behind, in case the
+ remove was an accident. Just issuing an installation request for the
+ accidentally removed package will restore its function as before in
+ that case. On the other hand you can get rid of these leftovers
+ by calling <command>purge</command> even on already removed
+ packages. Note that this does not affect any data or configuration
+ stored in your home directory.