PEP 622: Adopt a few clarifications (only) from python#1564

pep-0622.rst

@@ -1517,8 +1517,8 @@ ambiguous with capture patterns. Five other alternatives were considered:
   disambiguate grouping in patterns, e.g. in ``Point(x, y=(y :=
   complex()))``.
 
-* Introduce a special symbol, for example ``.``, ``$``, or ``^`` to
-  indicate that a given name is a constant to be matched against, not
+* Introduce a special symbol, for example ``.``, ``?``, ``$``, or ``^`` to
+  indicate that a given name is a value to be matched against, not
   to be assigned to.  An earlier version of this proposal used a
   leading-dot rule::
 
@@ -1554,7 +1554,9 @@ ambiguous with capture patterns. Five other alternatives were considered:
   * The authors are not aware of any other language that adorns
     captures in this way.
 
-  * None of the proposed syntaxes have any precedent in Python.
+  * None of the proposed syntaxes have any precedent in Python;
+    no other place in Python that binds names (e.g. ``import``,
+    ``def``, ``for``) uses special marker syntax.
 
   * It would break the syntactic parallels of the current grammar::