Crossref has supported depositing metadata for preprints since 2016 and peer reviews since 2018. Now we are putting the two together, in fact we will permit peer reviews to be registered for any record type.
This is a companion discussion topic for the original entry at https://0-www-crossref-org.pugwash.lib.warwick.ac.uk/blog/fast-citable-feedback-peer-reviews-for-preprints-and-other-record-types