This one

---------- Forwarded message ----------
From: Levente Uzonyi <>
Date: Wed, Nov 25, 2015 at 5:50 AM
Subject: Re: [squeak-dev] Removing of Universe classes
To: The general-purpose Squeak developers list <>

This question comes up from time to time.
There's an empty package named Squeak-Version in the image. When you unload a package, let's say Universes-mt.48, you add 49 (48 + 1) to the version number of Squeak-Version and save it as well to ensure that the global Squeak version number keeps increasing.