Issue #19795: Mark up None as literal text.
diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst
index 6894c7c..b763f10 100644
--- a/Doc/reference/datamodel.rst
+++ b/Doc/reference/datamodel.rst
@@ -767,7 +767,7 @@
dictionary containing the class's namespace; :attr:`~class.__bases__` is a
tuple (possibly empty or a singleton) containing the base classes, in the
order of their occurrence in the base class list; :attr:`__doc__` is the
- class's documentation string, or None if undefined.
+ class's documentation string, or ``None`` if undefined.
Class instances
.. index::