diff --git a/docker/services/README.rst b/docker/services/README.rst
index 8d1f9e86..60719bfc 100644
@@ -32,6 +32,11 @@ are re-asserted when applying latter ones.
* config_settings: Custom hiera settings for this service. These are
used to generate configs.
+ * kolla_config: Contains YAML that represents how to map config files
+ into the kolla container. This config file is typically mapped into
+ the container itself at the /var/lib/kolla/config_files/config.json
+ location and drives how kolla's external config mechanisms work.
* step_config: A puppet manifest that is used to step through the deployment
sequence. Each sequence is given a "step" (via hiera('step') that provides
information for when puppet classes should activate themselves.