Retentions are usually disclosed both in a library's local ILS/LSP, and also in OCLC. Shared print commitments are recorded in the MARC 583 field in accordance with the OCLC Detailed Metadata Guidelines.
Below is documentation for adding retention commitments in a variety of vendor platforms, including disclosing shared print in OCLC.
Record Retentions in your ILS
Sample guidelines from Shared Print Programs
Vendor Specific Instructions
Some programs also disclose their retentions in program wide databases. Here are some examples:
The Center for Research Libraries permanently retains titles which are discoverable in their catalog.
EAST - retention data is loaded into the Gold Rush Library Content Comparison System. Data is updated annually, and access to searching this data is granted upon request. The EAST website also provides a search box for OCLC numbers that queries registered retentions in OCLC.
Maine Shared Collections Cooperative provides a search box for OCLC numbers that queries registered retentions in OCLC.
PALNI has no formal retention commitments, but does have a shared discovery system in WorldCat.
SCELC has a Shared Print Discovery Catalog (SHARP)
VIVA - maintains an open Protected Titles database, ThistleCAT.