Per page 20 of Battle of Tukayyid, Battlefield Support Units can act as spotters for indirect fire, but nothing is stated as to how these units interact with the IDF rules in terms of modifiers. Per Total Warfare page 111, the Spotter's movement is taken into account for the Firer's attack mod, but BSP units have a flat +6 to hit and never apply the attacker movement mod. What modifier should be applied for the IDF attacker?