"Bookland" is the informal name for the Unique Country Code (UCC) prefix allocated in the 1980s for European Article Number (EAN) identifiers of published books, regardless of country of origin, so that the EAN namespace can catalogue books by ISBN rather than maintaining a redundant parallel numbering system.
In other words, Bookland is a fictitious country that exists solely in EAN for the purposes of non-geographically cataloguing books in the otherwise geographically keyed EAN coding system.
Until January 1, 2007, all ISBNs were allocated as 9-digit numbers followed by a modulo 11 checksum character that was either a decimal digit or the letter "X".
Most of UCC 979 (formerly "Musicland") has now been assigned for the expansion of Bookland,[3] and was first used by publishers in the French language, which can now use the additional prefix "979-10-" in addition to the nearly full "978-2-" prefix (onto which legacy 10-character ISBNs starting with "2-" have been remapped).
The "country codes" 978 and 979 are now officially registered for allocation by the International ISBN Agency, which maintains the official international registry of ISBN numbers allocated to book publishers.