linux/Documentation/admin-guide/abi-testing.rst

ABI testing symbols
===================

Documents interfaces that are felt to be stable,
as the main development of this interface has been completed.

The interface can be changed to add new features, but the
current interface will not break by doing this, unless grave
errors or security problems are found in them.

Userspace programs can start to rely on these interfaces, but they must
be aware of changes that can occur before these interfaces move to
be marked stable.

Programs that use these interfaces are strongly encouraged to add their
name to the description of these interfaces, so that the kernel
developers can easily notify them if any changes occur.

.. kernel-abi:: ABI/testing
   :rst: