Since April 2010 the Publications Office has assigned a digital object identifier (DOI) to each online issue of the Official Journal. You can find it in the upper right corner of the summary page of each OJ.
A DOI is a permanent digital identifier given to an object in the digital environment. Its most common application is to identify electronic documents, but it may also be applied to a photo, chapter, table, software, audiofile, etc. Each DOI is unique and permanent. A document keeps the same DOI for its entire lifetime and, should the document ever be deleted, the DOI will not be reused. In principle, the location of the DOI follows the same rules as the ISBN or ISSN.
DOI names are structured following a standardized syntax. They have two components, a prefix and a suffix separated by a forward slash.
An example of a DOI of an Official Journal L140 (2010) in English:
For more information on DOI visit www.doi.org.
A new FAQ 1.12 explaining the structure of CELEX numbers has been published recently. The Celex number is the unique identifier of each document in EUR-Lex, regardless of language.
We have also added a link to the table of sectors and descriptors.