Forward observer

A forward observer (FO) is an infantry team with special training to call indirect fire support of all kinds, including mortars, artillery and air support. Many of the heavier kinds of artillery can only be called by FOs.

Tactics

FOs are valuable assets which have to protected and therefore exposure has to be kept to a minimum. The following sequence of action helps to do this:

1. The FO needs a clear line of sight to the target action spot when making the initial call for the mission ("Requesting Fire Mission"). So give the fire order for the assets you want to use.
2. While transmitting the orders (between the Request and the end of the "Preparing" Phase of the asset), the FO does not need to see the target for several minutes. Thus you can hide the FO or even move it back into good cover. (The delivery time in the HUD area with the mission parameters should give you a good indication when the first spotting round will be delivered.)
3. The FO must see spotting rounds hit to adjust the fire. Thus, as soon as the "Spotting" phase starts for the asset, you need to have your FO back in the observation position.
4. After "Fire for Effect" has begun you can hide or pull the FO back again.

With this approach your FO will be exposed only during the moment when requesting the fire mission and during the spotting.

It is also wise to give a small cover arc to your FO so that they don't start to shoot at some opportunity target and expose themselves to enemy fire.

Officers (infantry, armor etc) can usually act as FOs for assets organic to the division.