Full Body Armour is listed on p437, core. Other armours may be considered full body, but I would hazard guessing that a defining feature of full body armour is that it; a) covers your entire body, and b) has a helmet that goes with it.
With this definition, we can include space suits and extreme environment (diving suits & any suit specialised to a specific type of armour modification - chemical, electrical, fire, radiation, etc) suits, survival suits (desert, arctic, etc), security (riot, SWAT, bunker, & milspec) armour, and others.
You may want to use a second definition, where the amount of armour provided defines whether or not something is 'full body'. FBA / SWAT / Light Milspec are 15, Riot is 14, and Sleeping Tiger / Murder Armour are 13 - any of those could be a valid cut off.
I also think it's worth leaving open to interpretation as to whether the bullet hole ridden armour you see is real armour, or whether the thick coveralls you see underneath contain gorepaks, with armour below that. After all, if it's that easy to pick out someone in murder armour, you can bet people will know what to look for, and it will be relegated to fooling amateurs only.