diff --git a/README.rst b/README.rst
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--- a/README.rst
+++ b/README.rst
@@ -1,8 +1,16 @@
 Glance Store Library
-=====================
+====================
 
 Glance's stores library
 
+This library has been extracted from the Glance source code for the
+specific use of the Glance and Glare projects.
+
+The API it exposes is not stable, has some shortcomings, and is not a
+general purpose interface. We would eventually like to change this,
+but for now using this library outside of Glance or Glare will not be
+supported by the core team.
+
 * License: Apache License, Version 2.0
 * Documentation: http://docs.openstack.org/developer/glance_store
 * Source: http://git.openstack.org/cgit/openstack/glance_store