| COMARC/B | February | 2008 |
This field contains an International Standard Music Number and a qualification which distinguishes between ISMNs when more than one is contained in a record. The field corresponds to the ISBD standard number (or alternative) and terms of availability area. The field may contain the terms of availability and/or price, even if it does not contain an ISMN.
A correctly applied ISMN including hyphens. The ISMNs are assigned by the designated agency in each country.
An indication of the scope of the ISMN in subfield a (if present): usually the name of a publisher, an indication of the binding of the item, or an indication of the relationship of an ISMN to a set or to a particular volume (see examples 1, 2). Within the COBISS software qualifications are entered without brackets because they are added automatically on display (see examples 4, 5).
The price of the item and any comment on its availability. Where there is an 010 – International Standard Book Number field and the contents of this subfield would simply repeat what is in 010d then the subfield can be omitted.
An ISMN that has been identified as being erroneously applied to an item or is otherwise invalid. It may have been allocated to two different publications and in this instance cancelled, or it may have been incorrectly printed (see example 3).
ISMN is used to identify music publications, whether available for sale, hire, gratis or for copyright purposes only, according to the provisions of ISO 10957.
Each separately available constituent part of a publication must receive its own ISMN. An ISMN consists of 10 or 13 digits. Whenever it is printed or written, a number is preceded by letters ISMN. In countries where the Latin alphabet is not used, an abbreviation in the local script may be used in addition to the Latin letters ISMN.
ISMN-10 consists of the letter M followed by nine digits. It is divided into four elements, two of which are of variable length, each of which is separated by a hyphen or space.
Distinguishing element: The letter M distinguishes the ISMN from the ISBN.
Publisher identifier: Designates the publisher of a given music publication. It is allocated to each publisher by a national or regional ISMN agency.
Item identifier: Identifies an edition of a work and the various items within it. An item, in the terms of the Standard, is one separately saleable or available or obtainable constituent part of a music publication.
Check digit: This is a single digit at the end of the ISMN that provides an automatic verification of the correctness of the ISMN. It is calculated on the basis of other numbers.
ISMN-13 consists of 13 digits. To 10-digit ISMN (ISMN-10) a suffix 979 is added; the letter M is replaced by zero (0). The publisher and the item identifier are the same as those at ISMN-10 (see example 6). ISMN-13 is identical as EAN for printed music.
The check digit for ISMN-10 or ISMN-13 is calculated on a modulus 10 with alternating weights of 1 and 3 assigned from left to right. For ISMN-10 the letter M counts as 3.
That means that each of the first nine digits of the ISMN-10, e.g. twelve digits of the ISMN-13 – i.e. excluding the check digit itself – is multiplied by an alternating sequence of the numbers 1 and 3 from left to right and that the sum of the products thus obtained, plus the check digit, must be divisible without remainder by 10.
The example for ISMN-10:
| Publisher identifier | Item identifier | Check digit | ||||||||
| ISMN | M | 3 | 4 | 5 | 2 | 4 | 6 | 8 | 0 | 5 |
| "Weight" | 3 | 1 | 3 | 1 | 3 | 1 | 3 | 1 | 3 | |
| Products | 9 | 3 | 12 | 5 | 6 | 4 | 18 | 8 | 0 | = 65 |
Total: 65 + 5 (check digit) = 70
As 70 can be divided by 10 without remainder M-345-24680-5 is a valid International Standard Music Number.
The example for ISMN-13:
| Prefix | Publisher identifier | Item identifier | Check digit | ||||||||||
| ISMN | 9 | 7 | 9 | 0 | 3 | 4 | 5 | 2 | 4 | 6 | 8 | 0 | 5 |
| "Weight" | 1 | 3 | 1 | 3 | 1 | 3 | 1 | 3 | 1 | 3 | 1 | 3 | |
| Products | 9 | 21 | 9 | 0 | 3 | 12 | 5 | 6 | 4 | 18 | 8 | 0 | = 95 |
Total: 95 + 5 (check digit) = 100
As 100 can be divided by 10 without remainder, 979-0-345-24680-5 is a valid International Standard Music Number.
The letters ISMN, which are usually found printed with an ISMN on the item, should not be entered in field 013.
Any ISMN which is found to be wrongly printed on the item can be entered in subfield 013z – Erroneous ISMN, which is provided to give access to records that may have been requested by an erroneous number appearing on the item.
Hyphens are inserted to separate the individual parts of the ISMN in subfields a and z. No other punctuation is permitted. When an ISMN is displayed in a catalogue entry the inclusion of the hyphens or spaces is mandatory. Many national agencies do not store the hyphens or spaces in the machine-readable record since they can be generated by algorithm if the range of publisher identifiers which have been allocated is known. When records are exchanged internationally the recipient of records may not always know the range of publisher identifiers. Therefore it is recommended that hyphens always be included in the ISMN in field 013 to ensure the display output.
Strictly speaking, each music publication has one ISMN. However, there are circumstances in which a single record may need to include more than one ISMN, depending on the policy of the cataloguing agency. Examples of situations in which multiple ISMNs might appear in a record are: where a publisher issues a work in more than one binding or physical format, each with different ISMN, and a single record is created by the agency encompassing more than one "editions", where a single record is created for a multi-volume publication and different ISMNs have been assigned by the publisher to each individual volume in the set and to the set as a whole; where a single item is published, or published and distributed, by more than one entity, each of which has assigned a separate ISMN to the item.
In order to distinguish between ISMNs when there are more than one in a record, qualifications may be added to one or more of them, according to the practise of the agency preparing the record.
Terms of availability and price are often related to each ISMN. Thus this information is recorded in the same field.
The field should be repeated for each valid ISMN. It should be repeated also for an invalid ISMN unless that invalid ISMN clearly relates to a known valid equivalent entered in the record, in which case the invalid ISMN will be entered in the same field as its corresponding valid ISMN (see example 3).
| 010 | INTERNATIONAL STANDARD BOOK NUMBER |
| The field contains the International Standard Book Number. It is sometime difficult to decide whether a publication is a music edition or a "normal" book, or both. In these cases both an ISMN and an ISBN may be assigned. | |
| 011 | ISSN |
| There are only a few periodicals of printed music, but many music publications are issued in series. Both categories should be assigned, an ISSN for the serial title and an ISMN for each individual item in the series. |
013 ⊔⊔ aM-706700-00-7 b(HDS) 013 ⊔⊔ aM-706701-00-4 b(MIC) (The item is published jointly by Hrvatsko društvo skladatelja and Muzički informativni centar.) 013 ⊔⊔ aM-9005202-2-7 b(bound) 013 ⊔⊔ aM-9005202-3-4 b(pbk) (The publication is available both in bound and in paperback edition.) 013 ⊔⊔ aM-9005202-1-0 zM-9005202-1-X (ISMN M-9005202-1-0 is incorrectly printed with an X as the check digit.) *
013 ⊔⊔ aM-008-04847-0 bSämtliche Werke 013 ⊔⊔ aM-008-04848-7 bViolinkonzert *
013 ⊔⊔ aM-001-11420-2 bBd. 7,1 013 ⊔⊔ aM-001-12205-4 bBd. 7,2 013 ⊔⊔ aM-001-12620-5 bBd. 7,3 *
013 ⊔⊔ a979-0-571-10051-3 (10-digit ISMNs not being used by a publisher (e.g. ISMN M-571-10051-3) may be used in a new 13-digit form. Check digits for 10- and 13-digit ISMN are identical.)