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.

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.

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¶

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

Item (Copy) → Abstract Work → Type–Token Distinction → Abstraction

Show alternative paths (2)

Neighborhood in Abstraction Space¶

Item (Copy) sits in a sparse region of the domain-specific corpus (63^rd percentile for distinctiveness): few abstractions share its structure, so a faithful description tends to retrieve it precisely.

Family — Authority Control & Identity (11 abstractions)

Nearest neighbors

Computed from structural-signature embeddings · 2026-07-12