Plate Number

Plate number is the number of the printing plate (or plates) depicted on postage stamp. It typically appears as one or more small digits in the margin at the bottom of the philatelic item. Although most plate numbers are composed of just figures, both a combination of letter and number may be used. In the case when a letter is represented in the plate number, an upper case character usually appears at the beginning or at the end of the sequence with the former serving as a good identifier of the stamp printer.