*Black* is a PEP 8 compliant opinionated formatter with its own style.
-It should be noted that while keeping the style unchanged throughout releases is a
-goal, the *Black* code style isn't set in stone. Sometimes it's modified in response to
-user feedback or even changes to the Python language!
+While keeping the style unchanged throughout releases has always been a goal,
+the *Black* code style isn't set in stone. It evolves to accommodate for new features
+in the Python language and, occasionally, in response to user feedback.
+
+Stability Policy
+----------------
+
+The following policy applies for the *Black* code style, in non pre-release
+versions of *Black*:
+
+- The same code, formatted with the same options, will produce the same
+ output for all releases in a given calendar year.
+
+ This means projects can safely use `black ~= 22.0` without worrying about
+ major formatting changes disrupting their project in 2022. We may still
+ fix bugs where *Black* crashes on some code, and make other improvements
+ that do not affect formatting.
+
+- The first release in a new calendar year *may* contain formatting changes,
+ although these will be minimised as much as possible. This is to allow for
+ improved formatting enabled by newer Python language syntax as well as due
+ to improvements in the formatting logic.
+
+- The ``--preview`` flag is exempt from this policy. There are no guarantees
+ around the stability of the output with that flag passed into *Black*. This
+ flag is intended for allowing experimentation with the proposed changes to
+ the *Black* code style.
Documentation for both the current and future styles can be found: