Indicate PEP 483 is sloppy about type vs. class.

pep-0483.txt

@@ -106,15 +106,20 @@ Notational conventions
 -  X, Y etc. are type variables (defined with TypeVar(), see below).
 -  C, D etc. are classes defined with a class statement.
 -  x, y etc. are objects or instances.
--  We use the terms type and class interchangeably, and we assume
-   type(x) is x.\_\_class\_\_.
+
+-  We use the terms type and class interchangeably.  Note that PEP 484
+   makes a distinction (a type is a concept for the type checker,
+   while a class is a runtime concept).  In this PEP we're only
+   interested in the types anyway, and if this bothers you, you can
+   reinterpret this PEP with every occurrence of "class" replaced by
+   "type".
 
 
 General rules
 -------------
 
 -  Instance-ness is derived from class-ness, e.g. x is an instance of
-   t1 if type(x) is a subclass of t1.
+   t1 if the type of x is a subclass of t1.
 -  No types defined below (i.e. Any, Union etc.) can be instantiated.
    (But non-abstract subclasses of Generic can be.)
 -  No types defined below can be subclassed, except for Generic and