Trinity College Library has treated official publications as part of a dedicated official publications (OPUB) collection for most of the twentieth century, with its own physical locations and its own shelfmark system. Most earlier publications are with the Department of Early Printed Books, selected items published after 2010 are integrated in the Library's subject collections, with the rest sent to storage. While some of the older material is not yet catalogued, all new publications are accessible through the Library's online catalogue.
The geographic scope of the OPUB collection is global in theory, and there are some minor holdings of publications from governments around the world. In practice, it is most complete for material from the Irish and British governments, as well as from the European Union and its predecessors: helped by the Library's function as UK and Irish copyright library since 1801, and as European Documentation Centre (EDC) since 1973. Holdings of publications from certain other inter-governmental organisations are also comprehensive, particularly from the OECD, the WHO, and the Commonwealth of Nations.
Specifically, this collection includes publications of parliaments, government departments and public authorities (including state-sponsored bodies), for example in the Irish case: Dáil Éireann, Department of Finance, Central Statistics Office, Combat Poverty Agency, Teagasc. Subordinate and colonial governments, for example Northern Ireland or Bermuda, are also included, but not local authorities, state companies and statutory corporations of a commercial nature, such as C.I.E.
The test for deciding whether an item is an official publication is the publisher: the Stationery Office in Dublin, TSO London, United Nations. An official publication is usually produced by a department, but sometimes may be the work of an individual author. Such a publication may need to be checked in the catalogues under the sponsoring department rather than the author's name.