terminology

Author: keewis

docs/terminology.rst

@@ -5,6 +5,7 @@ Terminology
 
     unit-like
         A `pint`_ unit definition, as accepted by :py:class:`pint.Unit`.
-        May be either a :py:class:`str` or a :py:class:`pint.Unit` instance.
+        May be a :py:class:`str`, a :py:class:`pint.Unit` instance or
+        :py:obj:`None`.
 
 .. _pint: https://pint.readthedocs.io/en/stable