strelaysrv(1) on Linux
The text 7b64bbf817d4, as Debian 10 (Buster) shipped it.
Syncthing Relay Server
Flags it lists
-
-debug -
-ext-address -
-global-rate -
-keys -
-message-timeout -
-nat -
-nat-lease -
-nat-renewal -
-nat-timeout -
-network-timeout -
-per-session-rate -
-ping-interval -
-protocol -
-provided-by