diff -r 99db0ca554d9 Doc/library/itertools.rst
--- a/Doc/library/itertools.rst	Mon Apr 14 13:13:01 2014 -0400
+++ b/Doc/library/itertools.rst	Mon Apr 14 14:52:03 2014 -0400
@@ -87,10 +87,13 @@
 
 .. function:: accumulate(iterable[, func])
 
-    Make an iterator that returns accumulated sums. Elements may be any addable
-    type including :class:`~decimal.Decimal` or :class:`~fractions.Fraction`.
-    If the optional *func* argument is supplied, it should be a function of two
-    arguments and it will be used instead of addition.
+    Make an iterator that returns accumulated sums, or accumulated results
+    of other binary functions (specified via the *func* argument). If said
+    optional *func* argument is supplied, it should be a function of two
+    arguments. Elements of the input *iterable* may be any type that can be
+    accepted as arguments to *func*. (So with the default operation of
+    addition, elements may be any addable type including
+    :class:`~decimal.Decimal` or :class:`~fractions.Fraction`.)
 
     Equivalent to::