Incorporate some suggestions by Tait Stevens.
diff --git a/Doc/tutorial/datastructures.rst b/Doc/tutorial/datastructures.rst
index fa71870..931f506 100644
--- a/Doc/tutorial/datastructures.rst
+++ b/Doc/tutorial/datastructures.rst
@@ -345,6 +345,7 @@
 Referencing the name ``a`` hereafter is an error (at least until another value
 is assigned to it).  We'll find other uses for :keyword:`del` later.
 
+.. _tut-tuples:
 
 .. _tut-tuples: