This powerful Daemonic standard is surrounded by potent spells of summoning. At the start of the battle, nominate one unit that must be summoned to be enslaved to the Icon. At the start of any Chaos turn, this unit can be automatically summoned – no roll to summon or scatter is required, simply place the Daemonic unit within 6" of the Icon. The unit can move in the movement phase and may make assaults as normal.
Chaos Icon
Source: Codex: Chaos Space Marines (1999), p. 28