[...]
New derivatives keyword
-----------------------
[...]
The Ubuntu distribution will be the first to make use of this new feature.
Each time that a new package is uploaded to Ubuntu, the PTS will receive
the diff between the new version and the previous one. This way we'll
receive regularly small patches instead of having only a big monolithic
patch on http://patches.ubuntu.com/ (those will continue to be updated
anyway). Those mails will look like this:
https://lists.ubuntu.com/archives/ubuntu-patches/2006-July/thread.html
[...]