The original proposal for an ISMN was made by the UK Branch of IAML, put forward by Alan Pope, Malcolm Lewis and Malcolm Jones. A draft ISMN structure and application was presented at the 1987 IAML conference in Amsterdam, then after further discussions at the 1989 IAML conference in Oxford it was decided that the UK, French and German branches should, through their respective national standards bodies file ISMN as an ISO work project. After meetings in Ottawa and Paris in 1993 the draft was finalized and published by ISO. The original format comprised four elements: a distinguishing prefix M, a publisher ID, an item ID, and a check digit, typically looking like M-2306-7118-7. From 1 January 2008 the ISMN was defined as a thirteen digit identifier beginning 979-0 where the zero replaced M in the old-style number. The resulting number is identical with its EAN-13 number as encoded in the item's barcode. The 979 Unique Country Code prefix is known as "Musicland". The current format comprises four blocks: the prefix 979-0 reserved for ISMNs — at some future date they are expected to occupy the remainder of the 979 space which is shared with ISBNs, a block to identify the publisher, another to identify the item and one final check digit. The TC 46/SC 9 is responsible for the standard. A publication may be assigned both an ISBN and an ISMN. Unlike the ISBN, the ISMN does not segregate publishers by country.
Check digit
To calculate the check digit, each digit of the ISMN is multiplied by a weight, alternating 1 and 3 left to right. These weighted digits are added together. The check digit is the integer between 0 and 9 that makes the sum a multiple of 10.
Examples
For instance, for the item with ISMN beginning 979-0-060-11561: As 85 mod 10 = 5, the check digit is 10 - 5 = 5 and the full number is 979-0-060-11561-5. For another example, Robert Fripp's collection of Guitar Craft scores has the ISMN 979-0-9016791-7-7. Given first 12 digits 979-0-9016791-7, the ISMN algorithm evaluates which implies that the check digit is indeed 7.
