+
+.. _new_abi_version:
+
+New ABI versions
+------------------
+
+A new ABI version may be declared aligned with a given release.
+The requirement to preserve compatibility with the previous major ABI version
+is then dropped for the duration of this release cycle.
+This is commonly known as the *ABI breakage window*,
+and some amended rules apply during this cycle:
+
+ * The requirement to preserve compatibility with the previous major ABI
+ version, as described in the section :ref:`abi_changes` does not apply.
+ * Contributors of compatibility preserving code in previous releases,
+ are now required to remove this compatibility code,
+ as described in the section :ref:`abi_changes`.
+ * Symbol versioning references to the old ABI version are updated
+ to reference the new ABI version,
+ as described in the section :ref:`deprecating_entire_abi`.
+ * Contributors of aliases to experimental in previous releases,
+ as described in section :ref:`aliasing_experimental_symbols`,
+ are now required to remove these aliases.
+ * Finally, the *ABI breakage window* is *not* permission to circumvent
+ the other aspects of the procedures to make ABI changes
+ described in :ref:`abi_changes`, that is, 3 ACKs of the requirement
+ to break the ABI and the observance of a deprecation notice
+ are still considered mandatory.
+