1 files changed, 5 insertions, 2 deletions
diff --git a/docs/templates.md b/docs/templates.md
index 2b66e9d862..b251d05cb9 100644
--- a/docs/templates.md
+++ b/docs/templates.md
@@ -176,8 +176,11 @@ Below are the templates Synapse will look for when generating pages related to S
              for the brand of the IdP
     * `user_attributes`: an object containing details about the user that
       we received from the IdP. May have the following attributes:
-        * display_name: the user's display_name
-        * emails: a list of email addresses
+        * `display_name`: the user's display name
+        * `emails`: a list of email addresses
+        * `localpart`: the local part of the Matrix user ID to register,
+          if `localpart_template` is set in the mapping provider configuration (empty
+          string if not)
   The template should render a form which submits the following fields:
     * `username`: the localpart of the user's chosen user id
 * `sso_new_user_consent.html`: HTML page allowing the user to consent to the