2025 September 11
Deprecating co-access: Crossref plans and timelines
TL;DR
To date, there are about 100 Crossref members who have made use of our co-access service for one or more of their books. The service was designed to be a last-resort measure when multiple parties - book publishers, aggregators, and other members - had rights to register book content. Unfortunately, the service allowed members to register multiple DOIs for shared books and book chapters, thereby violating our own core tenet of one DOI per content item. We should not have created a service that violated that tenet, resulting in duplicate DOIs; we’re retiring co-access at the end of 2026.
