Metadata Standards Working Group (April 2018)
PCC-LC Policy Statement 6.27 currently instructs us to “consider that a single series exists if some issues are numbered, but one or more issues are unnumbered.”
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When Harvard catalogers encounter in the course of their normal work a national-level series authority record with such qualifiers, they should contact Harvard’s NACO Coordinator, Mary Jane Cuneo (cuneo@fas.harvard.edu), so that she may they can cancel the SAR with the qualifier, and merge useful information from it into the remaining record following the normal NACO procedures for duplicates.
Please note that we are not undertaking a wholesale retrospective project, and that this guideline should not be construed as a mandate to seek out SARs that include such qualifiers. Resolving such duplicates can be more complicated than it seems, so catalogers are asked to report only series they encounter in the course of their normal work.
(This Harvard guideline replaces the former instructions, Guidelines for Handling Unnumbered Series distributed by the HUL Bibliographic Standards Working Group in February 2008 and revised in 2011.)