Whistle

Whistling
Whistling is a useful ingame non-verbal mechanic, by default bound to "F". It has various uses:
 * Commonly used to strike fear into the soul of the enemy
 * Hailing a nearby Friendly Vehicle
 * Getting a nearby player's attention (friendly or enemy)
 * Telling nearby allies that an enemy has been taken out (when whistling after gunfire)
 * Getting nearby teammates to follow you
 * Victory Cry
 * Mostly anything desired, as long as your team can vaguely understand its purpose
 * Can be used to harass enemy tankers into exiting their vehicle

Things to Note

 * It has a small cool down, so try not to spam it willy-nilly
 * Both friend and foe can hear it, so if you do whistle it will give nearby enemies a good reading on what your location is
 * When done near a friendly vehicle, it will display to them a small symbol over your head, informing them you want a ride