The National Library of Medicine adopted the 2019 MeSH vocabulary for cataloging on November 19. Accordingly, MeSH subject headings in LocatorPlus were changed to reflect the 2019 MeSH vocabulary and appear in that form as of November 19. When year-end processing (YEP) activities are completed in late November, the NLM Catalog database and translation tables will be updated to reflect 2019 MeSH. Until then, there will be a hiatus in the addition of new and edited bibliographic records to the NLM Catalog. The Winter version of the NLM Classification, to be published in mid-to-late-January 2019, will encompass changes resulting from new and changed MeSH terms for 2019 as well as additional minor updates to the index. The main index terms will continue to link to 2018 MeSH until the Winter 2019 edition is published in January.
An NLM Classification number appears in many terms in the MeSH Browser and is supplied annually by the NLM Cataloging and Metadata Section (CaMMS) when the MeSH term points to a single classification number in the Classification Index. These class numbers are current as of the Winter 2018 edition of the NLM Classification. They will be updated with the publication of the 2019 Winter edition in January.
For a complete list of updates, including changes and additions to qualifiers (subheadings) and publication types, visit the NLM Technical Bulletin.