Installation from a series of WWW URLs.  You must know the exact URL of the
Packages.gz files and the structure of the archive.

[ Note: this is not part of the standard dpkg package and is more
likely to produce errors due to differences between the Packages files
that are downloaded during the Update phase and what the archive
actually contains during the Install phase.  This also means that the
Update phase should be run fairly frequently to give a more accurate
picture of the archive to dselect. ]