A prime identifier associated with the document object for the purpose unambiguously identifying the specific object as a singular entity. The prime identifier is unique to the document object and cannot be duplicated.

The document number may be allocated manually by the user, or automatically by the system. The document number may be visible or transparent to the user.

The format of the document number is irrelevant and bears no significance to applied business logic.

The document number may consists of several data fields which in combination constitute the unique identifier for the document, i.e. document reference + document revision.

See also IDENTIFICATION. ATTRIBUTE, and DOCUMENT.