A digital object identifier (or doi) is a standard for persistently identifying electronic documents on a digital network . A typical use of a DOI is to give a scientific paper or article a unique identifying number that can be used by anyone to locate details of the paper, and possibly an electronic copy. Unlike the URL system used on the Internet for web pages, the DOI does not change over time, even if the article is relocated. This means that you can always find a document you have referenced even if the original publisher changes its URL.
The DOI consists of a unique alphanumeric character string divided in two parts: a prefix and a suffix. For example, a complete DOI is: 10.1000/182. Where 10.1000 is the prefix, or ''publisher ID'', composed by a part identifying the string as a DOI (10) and a part identifying the organization/publisher of the document (1000); 182 is the suffix, or ''item ID'', identifying the single object. (Typical suffices are longer than this example.)
The suffix is assigned by the publisher and must be unique within a prefix.
The International DOI Foundation (IDF), a non-profit organisation created in 1998, is the governance body of the DOI System, which safeguards all intellectual property rights relating to the DOI System. IDF supports the development and promotion of the Digital Object Identifier system as a common infrastructure for content management, and works to ensure that any improvements made to the DOI system (including creation, maintenance, registration, resolution and policymaking of DOIs) are available to any DOI registrant, and that no third party licenses might reasonably be required to practice the DOI standard.
See the International DOI Foundation FAQ for more information.