The IDDN number, attributed to the work by InterDeposit, has a three-tier function.

1. The IDDN number contains codified information that in particular covers :
   • the type of work, whether it is for example a primary work or a derivative work, i.e. one work created from another
   • the product class number, indicating for example if the work is a digital image or a program
   • the nationality of the work the year of referencing of the work
   • the year of referencing of the work
2. The IDDN number allows access to the InterDeposit database, containing the IDDN certificate which provides information on :
   • the title of the work
   • the holder of rights over the work and his or her e-mail address
   • any special conditions for the use and exploitation of the work, and there may possibly be a link to a payment interface
   • the sources of the referenced work, if it is an adaptation of another work. The certificate of the so-called "derivative" work indicates the IDDN number of the original work, or if this is not referenced, the certificate just indicates its indirect access (the place where the original work can be found)
   • the new status of the electronic signature of the IDDN base after the referencing of the work.
     This new status is the result of a combination of referencing information (title, type and electronic signature of the work, time and date, etc.) and the electronic signature of the IDDN base obtained at the time of the previous referencing. This process constitutes a guarantee of chronology and security.
3. The IDDN is the identity card of the digital work, particularly bearing information on any intellectual property rights over the work.