I maintain a package on launchpad that releases approx every month. However, our new version is no longer compatible with the previous version, because of some fundamental changes. So version 2.8 should not be upgraded to 2.9. I specifically want to prevent users from upgrading to 2.9 by mistake. Instead if they want to upgrade, they should be forced to apt-get remove, and then apt-get install to get a fresh install.

Is there a way to specify this in the package description? Or am I better of creating a separate repository or changing the name of the package?