Add missing label.

diff --git a/Doc/library/collections.rst b/Doc/library/collections.rst
index d78e7c93757783cb6160b77a0ce1bc1d5f93761a..e0b61218444462cae69b6d9a6f8e51a872eebb26 100644 (file)
--- a/Doc/library/collections.rst
+++ b/Doc/library/collections.rst
@@ -853,6 +853,8 @@ original insertion position is changed and moved to the end::
             OrderedDict.__setitem__(self, key, value)
 
 
+.. _abstract-base-classes:
+
 ABCs - abstract base classes
 ----------------------------