Dropped Packages

[Aurelio Turco <azt@bom.gov.au>]

It is possible for packages to become "dropped".

For example: you pick-up a package through
stable-proposed-updates that does not actually
make it into the next revision; or, in going
from one version of stable to the next, a
package is simply no longer included.

Is there any easy way to check for such
dropped packages?

Cheers.
Aurelio.