Issue #12531: add index entries to documentation of * and ** in function calls
diff --git a/Doc/reference/expressions.rst b/Doc/reference/expressions.rst
index f882952..d85a9c6 100644
--- a/Doc/reference/expressions.rst
+++ b/Doc/reference/expressions.rst
@@ -667,12 +667,15 @@
and the argument values as corresponding values), or a (new) empty dictionary if
there were no excess keyword arguments.
+.. index::
+ single: *; in function calls
+
If the syntax ``*expression`` appears in the function call, ``expression`` must
-evaluate to a sequence. Elements from this sequence are treated as if they were
-additional positional arguments; if there are positional arguments *x1*,...,
-*xN*, and ``expression`` evaluates to a sequence *y1*, ..., *yM*, this is
-equivalent to a call with M+N positional arguments *x1*, ..., *xN*, *y1*, ...,
-*yM*.
+evaluate to an iterable. Elements from this iterable are treated as if they
+were additional positional arguments; if there are positional arguments
+*x1*, ... ,*xN*, and ``expression`` evaluates to a sequence *y1*, ..., *yM*,
+this is equivalent to a call with M+N positional arguments *x1*, ..., *xN*,
+*y1*, ..., *yM*.
A consequence of this is that although the ``*expression`` syntax may appear
*after* some keyword arguments, it is processed *before* the keyword arguments
@@ -693,6 +696,9 @@
It is unusual for both keyword arguments and the ``*expression`` syntax to be
used in the same call, so in practice this confusion does not arise.
+.. index::
+ single: **; in function calls
+
If the syntax ``**expression`` appears in the function call, ``expression`` must
evaluate to a mapping, the contents of which are treated as additional keyword
arguments. In the case of a keyword appearing in both ``expression`` and as an