From Valve Developer Community
- The smoke grenade will not go off until it has come to a complete stop.
- The smoke grenade will nopt prime in your hand by holding the fire button.
- Once the smoke starts comming out, the grenade will not move.
- +attack will pull the pin to prepare for throwing. Letting go of your +attack key will throw the grenade.
- +attack2 does nothing.
- The smoke grenade is only given to the assault class.
- Some players video cards are not good enough render the smoke, so they can see through it, though it is a rare case.