Preprint Citation Index is a multidisciplinary collection of preprints from a wide range of leading preprint repositories. Web of Science (WoS) currently indexes five preprint servers: arXiv, bioRxiv, medRxiv, chemRxiv, preprints.org. The five repositories contain about 2 million records, however twenty more repositories will be indexed in the near future.
All records in the product contain standard bibliographic metadata such as author, abstract and keywords. The extended metadata includes the affiliation of the author, sponsor information and references. Version control metadata is not included in the database.
The presentation is available here.