"Robber" or "Thief"

A "robber" or "thief" is a small piece of scrap (often just a little piece of lead wire) which is attached to the plating rack, and whose purpose is to draw some of the plating current away from the high current density (HCD) areas of the component which is being plated, in order to protect that HCD area from "burning"

Robbers could theoretically be used for any type of plating, but in practice they are very widely used in chrome plating but largely unheard of otherwise.