International Systems Development Guidance

Systems developers are encouraged to consider the following when designing software

that interacts with ISBN:

ISBN data input 

 general considerations

While the ISBN standard defines a single 13 digit standard, 10 digit manifestations

associated with the 978 EAN.UCC prefix will be encountered within the supply chain for a

number of years. Developers should consider the degree to which input routines will

accept and convert 10 digit or 13 digit ISBN manifestations for internal system

requirements.

Where a 10 digit ISBN is being converted to a 13 digit ISBN, the prefix element 978

precedes the first 9 digits of the 10 digit ISBN and is followed by a check digit calculated

using the modulus 10 check digit formula in section 4.5.

As all EAN.UCC product identifiers may be represented in 14 digit form, it is

recommended that systems developers incorporate compliance with the GTIN in their

design. For further information on GTIN, please see section 13.2.

ISBN data input 

 validation considerations

Two levels of validation are available to confirm that input data is a plausible ISBN:

  Check digit validation (see section 4.5)

o

  The check digit validation process is a simple mathematical formula that

can be used to validate the internal consistency of ISBN input data. Check

digit validation will trap many data input errors but will not confirm that the

ISBN is for a registrant from a defined registrant group range. 

  Registrant group and registrant validation (see section 4.6)

o

  This two step formulaic process will validate that the registrant group is

defined and that the registrant range within that group is defined by the

International ISBN Agency. When either the registrant group or the

registrant group range is undefined, the ISBN is invalid. When the registrant

group and registrant range are defined, information from this process is

available to split the ISBN into its five elements:

  Prefix element

  Registration group element

  Registrant element

  Publication element

  Check digit

o

  The assignment and definition of registrant group ranges is an ongoing

process overseen by the International ISBN Agency. Current registrant

group range information will be available from a standard URL on the

International ISBN Agency website. System developers are encouraged to

check this URL on a regular basis for up to date validation and splitting

data.

ISBN data output 

general considerations

All external transmission of the ISBN should utilise the 13 digit manifestation after 

1 January 2007. 

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