diff --git a/doc/source/topics/settings.rst b/doc/source/topics/settings.rst
index 6e0cbd02d0..c18d65d4c1 100755
--- a/doc/source/topics/settings.rst
+++ b/doc/source/topics/settings.rst
@@ -654,7 +654,8 @@ with Keystone V3. All entities will be created in the default domain.
 Default: ``"_member_"``
 
 The name of the role which will be assigned to a user when added to a project.
-This name must correspond to a role name in Keystone.
+This value must correspond to an existing role name in Keystone. In general,
+the value should match the ``member_role_name`` defined in ``keystone.conf``.
 
 
 ``OPENSTACK_KEYSTONE_MULTIDOMAIN_SUPPORT``