koppellijn

koppellijn is a Dutch term that translates literally as “link line.” It is used primarily in bibliographic and publishing contexts to indicate an intentional connection between two or more items in a catalogue or printed work. In library science the koppellijn is part of the record structure that shows that a particular bibliographic record refers to another record, for example a monograph that is related to a companion volume or a multi‑volume set where one volume contains the continuation of a previous one. The line often appears as a small notation in a cataloguing interface or in the printed bibliography, signifying that the reader should consult the linked item for further information.

In the printing trade a koppellijn can also denote a typographical element that joins two parts of a spread or two adjacent images on a page, helping the reader to follow the visual narrative across page boundaries. In this sense the koppellijn is a design device that keeps the spatial continuity of printed material intact.

The concept originated in early 20th century Dutch library practice, when cataloguers began to formalise relationships between items. Over time the term has been adopted by digital library systems, where electronic koppellijnen are implemented as hyperlinks, thereby extending the original idea into the digital domain. The practice is recognised in the Dutch Library Association’s guidelines on advanced cataloguing and is an example of how a simple visual or textual symbol can carry complex relational information in information management.