.. function:: unregister(func)
- Remove *func* from the list of functions to be run at interpreter
- shutdown. After calling :func:`unregister`, *func* is guaranteed not to be
- called when the interpreter shuts down, even if it was registered more than
- once. :func:`unregister` silently does nothing if *func* was not previously
- registered.
+ Remove *func* from the list of functions to be run at interpreter shutdown.
+ :func:`unregister` silently does nothing if *func* was not previously
+ registered. If *func* has been registered more than once, every occurrence
+ of that function in the :mod:`atexit` call stack will be removed. Equality
+ comparisons (``==``) are used internally during unregistration, so function
+ references do not need to have matching identities.
.. seealso::