- Z is the revision. This has different meaning for stable and
unstable releases:
+
* Stable: Z is incremented when bugs get fixed without adding
- any new features.
+ any new features. This is intended to be convenient for
+ downstream distributors that want bug fixes but don't want
+ any new features to minimize the risk of introducing new bugs.
+
* Unstable: Z is just a counter. API or ABI of features added
in earlier unstable releases having the same X.Y may break.