FRAGO stands for Fragmentary Orders.
These are given by the Squad-leader and awards all the squadmembers who obey with double XP.
They can only be given by the squad-leader.
Killing enemy in, from or at FRAGO areas earn you the points. Also clearing objectives, healing teammates, reviving teammates, repairing equipment, practically anything done inside the FRAGO-areas earns you the bonus.
Using FRAGO correctly can turn the tides, but requires the individual squadmember to do his/her bit.