a block of stamps, traditionally four in number, but sometimes more, which has a plate number printed on the attached margin. Most collectors of plate blocks collect them in sizes as standardized by the Scott Catalogue.
A block of stamps with the margin attached that bears the plate number used in printing that sheet.
A block of stamps with attached selvage bearing the plate number used in printing the sheet.
A block of four or more stamps that has a code (plate number) printed on the margin (selvage) identifying the printing plate used in the stamps production.
A block of stamps from the corner or side of a pane including the selvage bearing the number(s) of the plate(s) used to print the sheet from which the pane was separated. Some stamp production methods, like booklet production, normally cut off plate numbers. Plate number blocks are collected normally as blocks of four to 20 stamps, depending on the press used to print the stamps. When each stamp in a pane is a different design, the entire pane is collected as the plate block.
Block of 4 or more stamps with the printing plate number in the margin.
A plate block, or plate-number block is a block of postage stamps that includes the part of the sheet margin with the serial number of the printing plate(s) used to print the stamps.
