Beginning December 2018, the Library of Congress’ PSD announced the cancellation of “multiple” subdivisions from Library of Congress Subject Headings (LCSH).
Established LCSH multiple subdivisions are identified by the presence of [square brackets] and followed by “etc.” The concept allowed catalogers flexibility in creating and maintaining LCSH heading strings as catalogers can “fill in the blank” and substitute any word, phrase, or other information that fits the instruction without seeking PSD approval. Unfortunately, the use of multiple subdivisions, which are not fully authorized, presents obstacles in implementing linked-data projects. Using multiples to generate free-floating lists under individual headings creates headings without identifiers and heading strings that cannot be machine-validated.
The announcement, which contains the project plan and instructions for catalogers, is found at