HECU

In-Game
HECU soldiers spawn with a good SMG that is a good starter until you get the M16 or the Remington shotgun

HECU engineers spawn with the same SMG as the soldiers but they get a tool which lets them build a total of three sentries which the sentries do low damage, have infinite ammunition, are immobile, the only good thing about them is that they have infinite ammo sentries can get destroyed by simply knocking them down note that sentries only attack xen creatures

HECU medics spawn with the same SMG as engineers and soldiers but they have a medkit which heals others

Identification
HECU Soldiers are identified from their gas masks and berets

HECU engineers are identified from their helmets and gas tanks on the back HECU medics are identified from their redcross Armbands and redcross helmets