As a follow-up to the recent NLM announcement about MeSH headings distributed after December 2015, the following guidelines on working with MeSH headings (http://www.loc.gov/aba/pcc/documents/PCCdeconstructedMeSH.docx) have been posted on the PCC website:
*** Medical Subject Headings (MeSH) in PCC Records Starting November 23, 2015, the National Library of Medicine (NLM) will no longer incorporate Geographic terms and Publication Types/Genres in one long subject string with Topical subjects and topical subdivisions in NLM MARC 21 distributed records (https://www.nlm.nih.gov/tsd/cataloging/unstringmesh.html). OCLC will be reloading all of NLM's records to deconstruct records previously distributed by NLM with strings. In addition, OCLC will be deconstructing all subjects coded with a 650 second indicator of 2, indicating that they are MeSH subjects in January 2016. Beginning in January 2016, PCC catalogers who have been adding and validating MeSH should follow the guidelines below when authenticating or maintaining PCC records. Adding MeSH headings to PCC records PCC catalogers who work with MeSH should follow NLM's current "Use of MeSH for cataloging" (https://www.nlm.nih.gov/tsd/cataloging/MeSH_CatPractices.html) when adding MeSH headings to any PCC records (new, copy, authenticated). Authenticating existing OCLC member copy records with MeSH headings When authenticating existing OCLC member copy records with MeSH headings for BIBCO or CONSER, 1. PCC catalogers who work with MeSH should evaluate appropriateness of the MeSH headings and record them in faceted form following NLM's current "Use of MeSH for cataloging" (https://www.nlm.nih.gov/tsd/cataloging/MeSH_CatPractices.html) 2. PCC catalogers who do not work with MeSH may leave the MeSH headings as they are Maintenance of PCC authenticated records All PCC catalogers may leave MeSH strings in PCC authenticated records as they are when doing maintenance on PCC authenticated records. *** The guidelines will be incorporated into the BIBCO Participant's Manual and the CONSER Cataloging Manual at the next revision. Sincerely, Hien Nguyen Acting BIBCO Coordinator Library of Congress
