diff --git a/oeps/processes/oep-0055/decisions/0001-use-backstage-to-support-maintainers.rst b/oeps/processes/oep-0055/decisions/0001-use-backstage-to-support-maintainers.rst
index b3e832dc7..9ee4c02e7 100644
--- a/oeps/processes/oep-0055/decisions/0001-use-backstage-to-support-maintainers.rst
+++ b/oeps/processes/oep-0055/decisions/0001-use-backstage-to-support-maintainers.rst
@@ -96,6 +96,9 @@ References
 
 * `catalog-info.yaml`_ spec definition
 
+* `Backstage system model`_ has detail about the different kinds of components
+  and how they connect to each other.
+
 * Sample ``catalog-info.yaml`` file:
 
   .. code:: yaml
@@ -136,5 +139,6 @@ References
       - '<another_component_or_resource>'
 
 .. _Backstage: https://backstage.io
+.. _Backstage system model: https://backstage.io/docs/features/software-catalog/system-model
 .. _catalog-info.yaml: https://backstage.io/docs/features/software-catalog/descriptor-format
 .. _single pane of glass: https://www.webopedia.com/definitions/single-pane-of-glass/