Bug#48311: What it really typically means

[Tomasz Wegrzanowski <maniek@beer.com>]

Package: apt
Version: 0.3.13

actual message is :
--- start ---
Package foo has no available version, but exists in the database.
This typically means that the package was mentioned in a dependency and 
never uploaded, or that it is an obsolete package.
--- end ---
This is not true.
This is most times when one didnt mention non-us and/or non-free in
/etc/apt/sources.list
better msg will be :
--- start ---
Package foo has no available version, but exists in the database.
This typically means that the package was mentioned in a dependency and 
never uploaded, that it is an obsolete package or that the package is in
non-us or non-free and you didnt mention them in /etc/apt/sources.list.
--- end ---
or something similar