Fix description of copyreg.pickle function
.. function:: pickle(type, function, constructor_ob=None)
Declares that *function* should be used as a "reduction" function for objects
- of type *type*. *function* should return either a string or a tuple
- containing two or three elements. See the :attr:`~pickle.Pickler.dispatch_table`
+ of type *type*. *function* must return either a string or a tuple
+ containing two or five elements. See the :attr:`~pickle.Pickler.dispatch_table`
for more details on the interface of *function*.
The *constructor_ob* parameter is a legacy feature and is now ignored, but if