ID tag
From Tardis Wiki, the free Doctor Who reference
ID tags or identifying badges appeared on the dome beneath the eyestalks of bronze Daleks and contemporary models in the Dalek hierarchy. (PROSE: Dalek Combat Training Manual) The four members of the Cult of Skaro, Dalek Sec, Caan, Jast and Thay, were each distinguished by their own ID tag. (TV: Army of Ghosts/Doomsday)