An International Standard Book Number is assigned only to some editions and variations of a book.
For example, the check digit for an ISBN-10 of 0-306-40615-? is calculated as follows:Adding 2 to 130 gives a multiple of 11 (because 132 = 1211)  this is the only number between 0 and 10 which does so
 The International Standard Music Number (ISMN) covers musical scores

