Illumination Shells are special munitions fired by Long Tom, Sniper and Thumper artillery. Illumination shells replace their normal payload with high-intensity flares, released over an area with miniature parachutes to slow their descent. Their primary use is for illumination and marking enemy units during nighttime and other low-light operations.
Utilize same rules as standard artillery munitions, however instead of dealing damage they negate any modifiers due to night or dawn/dusk conditions within the target area.
- Tactical Operations, p. 355, "Flechette Artillery"