Issue #19795: Improved markup of True/False constants.
diff --git a/Doc/library/io.rst b/Doc/library/io.rst
index cc6cc95..c866c98 100644
--- a/Doc/library/io.rst
+++ b/Doc/library/io.rst
@@ -278,7 +278,7 @@
 
    .. method:: readable()
 
-      Return ``True`` if the stream can be read from.  If False, :meth:`read`
+      Return ``True`` if the stream can be read from.  If ``False``, :meth:`read`
       will raise :exc:`IOError`.
 
    .. method:: readline(limit=-1)