+
+This plugin has two mandatory configuration option. You **must** set `--cas_url`
+to the url of a server offering CAS 2.0 authentication. You must also set the
+`--ca_file` to an absolute path to the file containing CA certificates used by
+the server (generally, aka under Debian, fixing that value to
+`/etc/ssl/certs/ca-certificates.crt` is sufficient).
+
+This plugin has two mandatory configuration option. You **must** set `--cas_url`
+to the url of a server offering CAS 2.0 authentication. You must also set the
+`--ca_file` to an absolute path to the file containing CA certificates used by
+the server (generally, aka under Debian, fixing that value to
+`/etc/ssl/certs/ca-certificates.crt` is sufficient).