When you are given a new server or workstation to administer, you generally want to find out quickly what is installed and what is special about this computer. One way to find out is to look at all the packages which have been added to the system, especially those which are not part of the original Linux distribution.
This function provides the latter capability. It extracts the packages which are not members of the distribution. It does this by comparing the vendor and distribution tags of the package. All packages which do not match the current distribution are shown. For each package, the package name, version, vendor and distribution are shown.