howto/gitlab.md

@@ -2831,6 +2831,10 @@ program which does the following:
  5. resend the message after changing the `X-GitLab-ConfidentialIssue`
     header to `redacted` to avoid loops
 
+The filter sends its logs to syslog with the mail facillity, so you can find
+logs on the gitlab server in `/var/log/mail.log` for example if you grep for
+`gitlab_confiden`.
+
 The canonical copy of the script is in our [fabric-tasks](https://gitlab.torproject.org/tpo/tpa/fabric-tasks)
 repository, in `gitlab_confidential_filter.py`.