diff --git a/source/admin_manual/list_of_events.rst b/source/admin_manual/list_of_events.rst
index c26304401d..9890a4fbdf 100644
--- a/source/admin_manual/list_of_events.rst
+++ b/source/admin_manual/list_of_events.rst
@@ -2273,6 +2273,7 @@ Events emitted when login process proxies a connection to a backend.
    :inherit: login_proxy_session
 
    :field error: If login to destination failed, contains the error.
+   :field error_code: If login to destination failed, contains the error_code.
    :field disconnect_side: Which side disconnected: ``client``, ``server``,
      ``proxy``.
    :field disconnect_reason: Reason for disconnection (empty = clean
@@ -2286,6 +2287,26 @@ Events emitted when login process proxies a connection to a backend.
    Connection to proxy destination has ended, either successfully or with
    error.
 
+   **List of error codes**
+
+   authorization_failed
+      User authorization failed.
+   temp_fail
+      Auth service reported temporary failure.
+   user_disabled
+      User is disabled.
+   password_expired
+      Password is expired.
+   invalid_base64
+       Challenge response was invalid BASE64.
+   login_disabled
+       Login is disabled.
+   invalid_mech
+       Used mechanism isn't supported.
+   cleartext_auth_disabled
+       Cleartext authentication is not enabled, use TLS.
+   anonymous_auth_disabled
+       Anonymous authentication is not enabled.
 
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 FTS-Dovecot