Can DOI be assigned to peer review data?
Thanks for the question. The short answer is yes! Peer reviews can be assigned DOIs, see Peer reviews markup guide - Crossref for guidance. This is for peer review reports that are made public.
If you have a non-public peer review process and would like to document some aspects of it, the best option is to use Crossmark metadata, see Version control, corrections, and retractions - Crossref. An example is at http://0-api-crossref-org.pugwash.lib.warwick.ac.uk/v1/works/10.1186/s12909-022-03162-8 (check the ‘assertions’ section of the metadata). The assertions with this work are displayed in its Crossmark dialog box Crossmark.