+### entry for the gateway's `tripe' user's key, with `TRIPE_GATEWAY' set to
+### any value, like
+###
+### environment="TRIPE_GATEWAY=t" ssh-rsa ...
+###
+### For backwards compatibility, it can also be set as the `tripe' user's
+### shell, with the `[tripe@SERVER:]PEER' indicator set as the forced
+### command. If there are no forced command or `TRIPE_*' environment
+### variables then it is assumed that a gateway is calling.