ISMN is an international standard for publications of musical scores. The abbreviation stands for International Standard Music Number which is a standard number 10957 from the International Standard Organization (ISO). The ISMN- system is a sister-system to ISBN-system and is only used to identify musical scores and score-related publications.
The National and University of Iceland is the service agent for the Icelandic musical score publications and is also responsible for the introduction and spreading of the system in Iceland. Each publisher can have a series of numbers or individual numbers allocated for a special item. The allocation of numbers and information is provided to publishers free of charge. A registry of Icelandic music publishers is created which forms a part of an international register, Music Publishers International ISMN Database.
ISBN numbers should not be used for sheet music or books of scores. However, books of scores and song-books can also have an ISBN number if they contain much text and/or illustrations.