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Item (Copy)

Promote the single physical or digital copy to a first-class bibliographic entity at the bottom of the Work–Expression–Manifestation–Item ladder, so copy-specific data and operations attach to one instance rather than the shared edition.

Version
v4 · 2026-09-28 · History
Domain-specific #
213
Domain group
Humanities
Origin domain
Linguistics & Semiotics
Subdomain
Bibliographic Modeling → Linguistics & Semiotics

Core Idea

An Item, in FRBR and its successors IFLA-LRM and BIBFRAME, is the most concrete tier of a four-level bibliographic hierarchy: a specific physical or digital copy embodying a Manifestation (a publication or edition), which embodies an Expression (a realization), which realizes the Work (the abstract creation). FRBR's structural move is to promote the Item to a first-class entity with its own record, so copy-specific data and operations attach to one instance.

How would you explain it like I'm…

This Exact Copy

A library might have lots of copies of the same book. The Item is one exact copy — the one you're holding, with its own sticker, its own spot on the shelf, and maybe a coffee stain. When you borrow a book, you borrow that one copy, not every copy.

One Real Copy

Libraries describe books at different levels. At the top is the story or idea itself; then a version of it, like a translation; then a particular published edition, like one paperback printing. The Item is the bottom level: one single, real copy of that edition. Each Item gets its own barcode, shelf location, and notes, like whether it's checked out or has a torn page. When you check out a book, the library records that you have that exact Item. If a copy gets ruined and thrown away, only that Item is removed — the edition and the other copies are still in the catalog.

Individual Copy Record

In library cataloging models such as FRBR (and its successors IFLA-LRM and BIBFRAME), a creation is described in four levels: the Work (the abstract creation), an Expression (a particular realization of it, like a translation), a Manifestation (a specific publication or edition), and the Item (one individual physical or digital copy). The Item is the most concrete level. The key move is to treat each Item as a separate entity with its own identifier and record. Data shared by all copies — publisher, edition, ISBN, format — lives on the Manifestation record, while data specific to one copy — barcode, call number, shelf location, loan status, condition, provenance — lives on the Item record. That's why a loan is recorded against a particular copy, and why withdrawing a damaged copy leaves the edition and other copies untouched.

 

In FRBR and its successors IFLA-LRM and BIBFRAME, the Item is the most concrete tier of the Work–Expression–Manifestation–Item hierarchy: a specific, singular physical or digital copy that exemplifies a Manifestation, which embodies an Expression, which realizes a Work. FRBR makes the Item a first-class entity with its own record and identifier, separable from the Manifestation it belongs to, because the two carry different properties and support different operations. The Manifestation record holds publication-level data common to every copy — publisher, edition statement, ISBN, format, pagination — whereas the Item record holds instance-specific data such as call number, barcode, acquisition date, shelf location, circulation status, condition, provenance, and copy-specific annotations. Circulation, conservation notes, availability checks for interlibrary loan, and withdrawal all operate at the Item level; one Manifestation may link to many sibling Items. The same pattern — an individually identified instance with its own metadata, linked up to a shared higher-level record — recurs in museum accession records, archival box-and-folder descriptions, and digital asset management of specific files.

Scope of Application

The Item lives within bibliographic and cultural-heritage modeling, the subfields aligned with the FRBR / IFLA-LRM / BIBFRAME four-tier ladder.

  • Library cataloging — the home: one Manifestation record links to per-copy Item records for loans and withdrawals.
  • Museum object records — the accession-numbered artifact versus the type or workshop.
  • Archival finding aids — the specific folder in a specific box versus the series.
  • Digital asset management — a specific file at a specific path with a checksum versus its content.
  • Interlibrary loan — availability resolved at the Item level, not the edition.

Clarity

Naming the Item makes legible the difference between this book and this kind of book. Each property gets a level to live at: publication-level data (publisher, ISBN, pagination) sits at the Manifestation, instance-level data (location, condition, loan status) at the Item. It clarifies why a loan is recorded against an Item and why withdrawing a damaged copy retires one Item alone.

Manages Complexity

A mass of facts about many copies of many editions gets one placement rule: does this belong to the shared publication or the individual instantiation? A holding of hundreds of copies becomes one Manifestation record plus per-copy Items carrying only what differs, and copy-level queries collapse from ill-posed to well-typed at a known tier.

Abstract Reasoning

The model licenses property-placement (type a datum to its tier by an operational test), diagnostic reading (a misbehaving query reveals a promotion or placement fault), interventionist prediction (a copy-level operation's blast radius is exactly one Item), and boundary-drawing on what counts as a distinct instantiation under a fixed cardinality.

Knowledge Transfer

Within bibliographic and cultural-heritage modeling the Item discipline transfers as mechanism across library, museum, archival, and digital-asset records, the placement rule and diagnostics carrying intact. Beyond it the substrate-independent parent is the type/token (class/instance) distinction, which genuinely recurs in OO classes, serial-numbered banknotes, and build artifacts. That parent carries the lesson; the four-tier ladder and cataloging machinery stay home. dag_edges:

Relationships to Other Abstractions

Local relationship map for Item (Copy)Parents appear above the current abstraction, mutual partners to the right, and children below. Node labels state whether each abstraction is prime or domain-specific; colors identify relation types.Item (Copy)DOMAINPrime abstraction: Abstract Work — presupposesAbstract WorkPRIMEPrime abstraction: Type–Token Distinction — is a decomposition ofType–TokenDistinctionPRIME

Current abstraction Item (Copy) Domain-specific

Parents (2) — more general patterns this builds on

  • Item (Copy) presupposes Abstract Work Prime

    Calling one copy an Item at the bottom of WEMI presupposes a content identity that persists above its concrete carriers and fixes which variations remain realizations of the same Work.

  • Item (Copy) is a decomposition of Type–Token Distinction Prime

    Removing the child’s frame leaves the reusable structure named by Type Token Distinction.

Hierarchy paths (3) — routes to 1 parentless root

Neighborhood in Abstraction Space

Item (Copy) sits in a sparse region of the domain-specific corpus (69th percentile for distinctiveness): few abstractions share its structure, so a faithful description tends to retrieve it precisely.

Family — Information Control & Disclosure Failures (5 abstractions)

Nearest neighbors

Computed from structural-signature embeddings · 2026-10-08