How to Identify
Digital Surrogates

While they are not a replacement for print retentions, digital surrogates can be helpful tools for shared print programs when they assess how risk affects access to titles. As shared print programs work to accurately identify the scope and risk factors to their retained print collections, some of their member libraries have already begun to identify cases where a print item has an equivalent digital version that helps mitigate risk and/or have begun to digitize local print retentions that are at risk.

Resources for Working with and Identifying Committed Digital Surrogates

The Best Practice for Print to Digital Validation Work for Shared Print Programs helps shared print programs and member libraries develop processes for comparing a print copy to a digital copy, for validating the digital copy, and for documenting relevant data in the shared print commitment’s metadata. 

The CDL, CRL, and HathiTrust’s Shared Print Collaboration’s (CCH Collab) Collection Comparison Tool enhances shared print programs’ and member libraries’ ability to discover not only committed serials but also digital copies. The collection comparison tool brings together the shared print retention commitments registered in CRL’s Print Archives Preservation Registry (PAPR), HathiTrust digital collection metadata, and various libraries’ local serials data (submitted by users). The collection comparison tool requires an upload of OCLC numbers or ISSNs from local serial records relating to the data of interest. Libraries upload a file with OCNs or ISSNs related to the collection they are working on, and the report will match it to the repositories listed above to give libraries an overlap of holdings.

Methods for Identifying Digital Surrogates in Metadata 

According to contemporary cataloging practice, digital surrogates should be described in separate bibliographic records from the print/physical original. Depending on institutional practice, separate records for the digital surrogate and the print version may refer to each other via the 776 field (see GPO examples below), and the 856 41 is used in either or both records to indicate the digital surrogate’s URL and program source (e.g., Google Books, HathiTrust). In earlier cataloging practice, the 856 field in the print record was used to represent the digital surrogate rather than the creation of a separate record.

CRL Example of Metadata for a Digital Surrogate
This is the record for the digital surrogate.  Note use of the 856 field for an online resource and the source of the digital surrogate. It also identifies the print version in the 776 field.

Example from the MAC proposal 2019-01

Printed Resource, Enriched by Information About Electronic Versions in Field 856 Subfields $e and $7

See Congress Network Development and MARC Standards Office. (2018, December 12). MARC PROPOSAL NO. 2019-01. Retrieved June 3, 2019,

Example GPO Records

Online record for OCLC #604660376 with GoogleBook, HathiTrust, and GPO links and a 776 for the print record. (pdf)

Print record at OCLC #46804073 with multiple GPO links and two 776 to online records. The presence of the two 776s in the print record and the divergence in the links between the records illustrate some of the record maintenance issues that occur. (pdf)

Last Updated December 2022