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Shared inventory data dictionary

ReShare Shared Inventory brings together bibliographic, holding, and item metadata from a consortium to support discovery and fulfillment processes. This page describes the structure of the Shared Inventory records and the functions of important data elements.

Record structure

Instance records are similar to bibliographic records, but with a simplified set of fields. They describe a global version of a particular resource, and are generally scoped to the edition-level. In the Shared Inventory, each instance record represents a bibliographic resource that is held by at least one member of the consortium.

Holding records describe a particular institution’s unique holding of an instance, including location and lending policies. Holdings may represent a single item, a multi-volume set of items, or a serial publication.

Item records describe each individual copy or piece of a holding that is owned by an institution. Each item record typically represents a single physical object identified by a barcode. A holding may have more than one item attached. Multiple items may represent multiple copies of the same volume or multiple volumes of a set or serial.

Important data for ReShare

This documentation will not attempt to describe every field on a Shared Inventory record, much of which is standard bibliographic data that should be familiar to most library workers. Instead, it will highlight the fields that play unique and active roles in ReShare’s processes.


Data element


Data element


Matchkey (Index title)

A matchkey is created for each record upon ingest, based on a process used by the Gold Rush management system. The matchkey uses portions of the title, author, publisher, and other MARC fields to recreate a unique key for each record. Records with the same matchkey are associated with the same Shared Index Instance record, and a unique holdings record is created for each library that contributes a copy of the record.

The matchkey is displayed on each instance record for troubleshooting purposes. If you see errors in a matchkey that are causing false positives or false negatives, these errors must be corrected in the source data. Matches cannot be manipulated in the shared index itself.

Note that at this time the matchkey is stored in the “index title” field. This is a temporary solution. ReShare plans to add a dedicated matchkey field and contribute this code back to the main branch of the FOLIO code.

Resource ID

Each instance record can contain multiple resource IDs. Each ID is a key-value pair that includes an identifier type and the identifier itself. This field can be used for standard identifiers like ISSNs, ISBNs, OCLC numbers, etc.

In the ReShare context, this field is used to store the unique identifier of each source bib record that is associated with the instance. This generally corresponds to the 001 of the original record, but may vary by source system. Each ReShare identifier will have a type that matches the ReShare symbol of the contributing library – for example, US-PPT.

These resource IDs are used by ReShare’s fulfillment process. Once a supplier is assigned, ReShare will use that institution’s resource identifier to perform a real-time availability check using Z39.50 and automatically respond to the request.

Holdings fields

Data element


Data element


Holdings location - permanent

Each holding record has a location that will be populated based on the incoming data from each library that contributes a copy of a record. The list of holdings attached to an item represent the libraries within a consortium that hold that item.

In cases where holdings are not available, ReShare will automatically create a holding for each library location and group all items in that location underneath it.

FOLIO supports both a permanent and temporary holding location. At this time, ReShare uses only the permanent location.

ILL policy

The ILL policy field is used to indicate whether the items grouped underneath a particular holding can loaned using ReShare Returnables. The values recognized by ReShare are “Will lend” and “Will not lend.”

Item fields

Data element


Data element


Material type

Each item record has a material type. Because item material types vary widely between libraries, ReShare maps all incoming material types to standardized list derived from the MARC standard. Supported material types include:

  • BKS - Books

  • CNR - Continuing Resources

  • COM - Computer Files

  • MAP - Maps

  • MIX - Mixed Materials

  • REC - Sound Recordings

  • SCO - Scores

  • VIS - Visual Materials


Libraries contributing to the Shared Inventory are required to submit barcodes for each item they contribute. Item barcodes uniquely identify an item at its home institution. They can be used to search for an item in ReShare’s VuFind implementation.

Effective location

ReShare stores location information at the holding level. An item’s effective location will be by default the same as that of its parent holding.


All items in ReShare will have a default status of “Unknown” at this time. ReShare does not currently support import of live circulation statuses, though this has been identified as a future area of enhancement.

Operated as a Community Resource by the Open Library Foundation