The work is concerned with identification of bad signatures in a sequence which is validated using batching. Identification codes (id-codes) are defined and their general properties are investigated. A taxonomy of id-codes is given. The generic construction for a wide range of id-codes is given and its instantiation using mutually orthogonal Latin squares is described. Hierarchical identification is studied for two cases when the identification procedure uses a family of id-codes and when there is a single underlying id-code. Remarks about future research conclude the work.