I dont know about the default commands, but since boat switch aft puts you in dogfight mode, boat switch fwd probably puts you in MRM (medium range missile) mode. In this mode, you use the fcr (radar on mfd) to lock bandits. DMS down to make the radar SOI (sensor of interest), slew the cursor over a bandit, then TMS up once for a soft lock (SAM, situational awareness mode. Good enough for AMRAAMs and allows the radar to spot additional bandits in the direction of the target) and optionally another TMS up press for a hard lock (STT)