Remove XXX comment that was displayed.
diff --git a/Doc/library/constants.rst b/Doc/library/constants.rst
index f734b5c..89b7d71 100644
--- a/Doc/library/constants.rst
+++ b/Doc/library/constants.rst
@@ -40,10 +40,8 @@
.. data:: Ellipsis
- The same as ``...``. Special value used mostly in conjunction with extended
- slicing syntax for user-defined container data types, as in ::
-
- .. XXX Someone who understands extended slicing should fill in here.
+ The same as ``...``. Special value used mostly in conjunction with extended
+ slicing syntax for user-defined container data types.
.. data:: __debug__