diff --git a/specs/template.rst b/specs/template.rst
index ce6c129..9dd60b8 100644
--- a/specs/template.rst
+++ b/specs/template.rst
@@ -44,6 +44,15 @@ Some notes about using this template:
   having to look at additional files which can not be viewed in Gerrit.  It
   will also allow inline feedback on the diagram itself.
 
+* If your specification proposes any changes to the Ceilometer REST API such
+  as changing parameters which can be returned or accepted, or even
+  the semantics of what happens when a client calls into the API, then
+  you should add the APIImpact flag to the commit message. Specifications with
+  the APIImpact flag can be found with the following query::
+
+  https://review.openstack.org/#/q/status:open+project:openstack/ceilometer-specs+message:apiimpact,n,z
+
+
 Problem description
 ===================