diff --git a/roles/percona_xtradb_cluster/defaults/main.yml b/roles/percona_xtradb_cluster/defaults/main.yml
index 53583c4..c8542e8 100644
--- a/roles/percona_xtradb_cluster/defaults/main.yml
+++ b/roles/percona_xtradb_cluster/defaults/main.yml
@@ -1,4 +1,6 @@
 # This variable allows you to add configuration options to `spec` field on the
 # PerconaXtraDBCluster object in Kubernetes.  It can be used to enable features
 # such as backups.
+#
+# See: https://docs.percona.com/percona-operator-for-mysql/pxc/backups.html
 percona_xtradb_cluster_spec: {}