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WEMI is an acronym standing for Work, Expression, Manifestation, and Item—terms deriving from Functional Requirements for Bibliographic Records (FRBR), which is the primary means of describing bibliographic records.

Consequently, WEMI is the foundation both for FRBRoo, the CRM-compliant Linked Open Data (LOD) version of the conceptual model, and LRMoo, which will replace FRBRoo once approved by the CIDOC CRM Special Interest Group.

In WEMI, the Work represents the story, song, poem, or intangible form of a work. The Expression represents a specific form of the Work, such as an English text (Expression) of a story (Work). A Manifestation represents a specific published or produced Expression, such as a Penguin edition (Manifestation) of an English text (Expression) of a story (Work). The Item represents the individual unit of the Manifestation, such as the McLaughlin Library’s copy (Item) of the Penguin edition (Manifestation) of an English text (Expression) of a story (Work). In short, a Work is realized through an Expression; an Expression is embodied in a Manifestation; and a Manifestation is exemplified by an Item (Library of Congress, 2004).

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