[@TheShadow@]

if you press the Taxi Mission Key your "Weaponset" will change, so you get a Spas12 Shotgun, a Desert Eagle and a Sniper Rifle, instead of the other weapon set: Sawnoff, Tec9 Uzi, M4.
It's to change your weapons in a fight without typing a command, so you can wear 2 Shotguns Or 2 maschine guns or uzis and so on.
Understand it now?

Any more comments?