[Edit]

Accession number (bioinformatics), a unique identifier given to a biological polymer sequence (DNA, protein) when it is submitted to a sequence database.

Accession number (library science), the sequential number given to each new book, magazine subscription, or recording as it is entered in the catalog of a library.

Accession number (medicine), a test order unique identifier used in hospitals, in particular those using LIS station methodology. Image data is stored on the disk drive (archive) without any identifying information regarding the Patient's name or ID as part of the filename. The default filename will be an Accession number, if it is available in the incoming data, or a Study/Series UID, which is a set of digits with no apparent meaning to the casual observer