+.It Va ECDSAPrivateKeyFile Li = Ar filename Po Pa @sysconfdir@/tinc/ Ns Ar NETNAME Ns Pa /ecdsa_key.priv Pc
+The file in which the private ECDSA key of this tinc daemon resides.
+This is only used if
+.Va ExperimentalProtocol
+is enabled.
+
+.It Va ExperimentalProtocol Li = yes | no Po no Pc Bq experimental
+When this option is enabled, experimental protocol enhancements will be used.
+Ephemeral ECDH will be used for key exchanges,
+and ECDSA will be used instead of RSA for authentication.
+When enabled, an ECDSA key must have been generated before with
+.Nm tincctl generate-ecdsa-keys .
+The experimental protocol may change at any time,
+and there is no guarantee that tinc will run stable when it is used.
+