diff --git a/config/site_settings.yml b/config/site_settings.yml
index eb06163c072..7a9f2c2ac43 100644
--- a/config/site_settings.yml
+++ b/config/site_settings.yml
@@ -10,6 +10,7 @@
 #           Set to the class name that defines the set.
 # type: email    - Must be a valid email address.
 # type: username - Must match the username of an existing user.
+# type: list     - A list of values, chosen from a set of valid values defined in the choices option.
 required:
   title:
     client: true