Glossary for Discovery, our catalogue

Term Definition
Archive (held by) This is the organisation which holds the records – the may be known variously as record offices or repositories.
Catalogue reference see Document reference
Department code The highest level of The National Archives’ catalogue hierarchy, determined by the government department which held the records prior to The National Archives. Examples include Ministry of Health, War Office and Treasury.
Division An administrative section of a department, one level down.
Item Part of a ‘piece’; an item can be a page, a folder or a bundle of papers. Note that only a minority of records have been described to this level and therefore not all documents have an item number.
Piece Usually the level at which a reference becomes an orderable or viewable unit. A piece can be a folder, file, volume or box of documents.
Record creator The institution or person that originally created a record (often not the same as the institution or person that currently holds the record). For example, the Brookwood Cemetery burial registers were created by the London Necropolis Company and are held in the Surrey History Centre.
Document reference Every document held at The National Archives and other archives and institutions has a unique code, known as a document reference. Document references at The National Archives are usually in three parts. For example WO 95/234 – WO is the department, 95 is the series and 234 is the piece. References used by other archives may look different but follow a similar pattern, such as COL/CN/05/018 or LINCOLN PRISON 1.
Series The main grouping of records with a common function or subject. Archive documents maintained as a unit because they result from the same activity or filing process or have a particular form; or because of some other relationship arising from their creation, accumulation or use.
Subject Lists the subjects that the records have been tagged by, for example, railway, education, battles and conflicts.
Sub-series A smaller grouping of records with a common function or subject.
Sub sub-series A smaller grouping of records with a common function or subject.