As more and more journals are becoming digital – with several being exclusively available in digital format – it is increasingly important to establish viable means for ensuring free access to back issues of mathematical journals. For the mathematics community, it would be optimal to have the shortest possible window before open access. On the other hand, a short window would put financial pressure on learned societies and make it difficult to reach a broad agreement.

The IMU Executive Committee (EC) – on the advice of the IMU Committee on Electronic Information and Communication – created in 2021 an ad hoc Committee on Permissions with the task of preparing a report regarding the following:

• A recommendation for IMU policy on the time frame for making papers freely available after publication, together with technical details such as licenses.
• A concrete proposal for how to implement this recommendation, for example by outreach to publishers, with the particular goal of negotiating access to existing back issues.
• Any additional considerations that may affect the availability of past papers, such as the demise of publishing companies or issues with archiving.

The members of the Committee on Permissions were:

• Thomas Brennan, chair (Harvard Law School, US),
• Henry Cohn (US),
• Samuel Hansen (US),
• Evelyne Miot (France),
• Valeria Simoncini (Italy),
• Stephen Watt (Canada).

The Committee on Permissions met from 2021 to 2024 and submitted its final report to the IMU EC in August 2024. This final report has been endorsed by the IMU EC. Please find the endorsed report below.