ISBN (Bookland)

An ISBN barcode is an EAN-13 symbol whose thirteen digits open with the 978 or 979 prefix set aside for books, the notional Bookland country code. Since 2007 the International Standard Book Number itself has been thirteen digits, aligning identifier and barcode exactly and ending the earlier practice of converting a ten-digit ISBN before printing. The physical symbol is an ordinary EAN-13: a 0.264 mm X-dimension, a 22.85 mm bar height, a 1:1.5 aspect ratio, and quiet zones of eleven and seven modules. Publishers frequently pair it with an EAN-5 supplement carrying the suggested retail price. ISO Technical Committee 46 maintains the underlying standard. Because the symbol is structurally an EAN-13, retail scanners read it without modification, and the number functions as a GTIN-13 throughout the book supply chain.