Brief history of the Wessex classmarks

The National Library of Medicine (NLM) in Washington DC, USA published the first edition of their library classification scheme in 1951.

This covered the field of medicine and its related sciences whilst the various schedules of the Library of Congress classification scheme (LC) supplemented NLM classes for subjects other than medicine. NLM is now published electronically and updated annually. 

In the early 1980s the librarians of the Wessex Regional Library and Information Service (WRLIS) based in Dorset, Hampshire and Wiltshire took the decision to revise the whole of the United States National Library of Medicine (NLM) Classification schedules to accommodate current British medical practice. This work was originally in liaison with colleagues from other regions and the newly-formed national NLM Classification User Group.

Generally the classification letters are the same as NLM, but the numbers in the class marks may be different e.g. Midwifery is at WQ140 in Wessex, but WQ160 in NLM. Classification of nursing books though, can be quite different as Wessex often places specialty specific books with the specialty (e.g. Cancer Nursing in QZ) whereas NLM holds them in WY.  However, a major difference in the two classification schemes is the addition of WLM into the Wessex scheme to cover psychology, whereas for NLM this topic is classified in their more general collections using the Library of Congress classification section BF.

In addition to the classification schedules the Wessex team also developed, as an index, a version of annotated MeSH that combines the broader terms of NLM’s Medical Subject Headings (MeSH) with a number of extra terms that reflect concepts particular to the UK health sector. A shortened form of this doubles as a printable “where to find a book” index for library users.

The first edition of the Wessex Classification Scheme was formally published in 1987 and it continued to develop under the auspices of SWRLIN (South and West Regional Library Information Network) until 1999 when a 3rd revision of the classification scheme was published. After a brief survey of usage carried out in 2004 indicated the scheme was in use across the UK in a number of varied settings and circumstances (including hybrid Wessex/NLM schemes), further extensive consultation brought the 4th revision, keeping it fit for purpose with new union catalogues and shared library management systems being developed in many regions.

The 5th revision began in 2009 and was completed in 2013 with significant updating of the early sections, WE, and more minor updates to the rest of the classification, including terms to reflect the new structures of the reformed NHS. Significant expansion of the Annotated Subject Headings Index, with new terms and cross references, accompanied this revision.

Since this time the scheme has been updated by the SWIMS Network Cataloguing Group, supported by a number of other users from across the country via the email discussion list. The Annotated Subject Headings Index has also been maintained by the SWIMS Network Cataloguing Group, to incorporate changing issues in UK health care and annual updates to MeSH and NLM. 

Following a national survey in 2022 a new national working group was formed to undertake the oversight of the scheme and its updating. The Wessex Classification Scheme Oversight Group has a site on FutureNHS, and is supported by NHS England. All users of the scheme are encouraged to offer feedback and suggest changes and/or additions. For more information, contact Jason Curtis, the lead for the Wessex Classification Scheme at [email protected] 

All those who have worked on it are conscious that the Wessex Classification Scheme is not perfect. The scheme cannot match the speed of change in health care even though it is a dynamic entity. It has been developed over a period of time by many different librarians, often working voluntarily and in their own time. Its publication on the web is an attempt to share that work with library colleagues. However, all users are free to adopt parts of the scheme, or modify it as needed. 

We would like to acknowledge the guidance of the National Library of Medicine. NLM have asked us to make it clear that the Wessex Scheme is not an official NLM revision of its classification scheme and it is the product of the local efforts of UK health librarians. The National Library of Medicine neither endorses nor supports the Wessex Scheme.