A preprint server is a data repository that hosts scholarly articles before they have been formally peer-reviewed and published. Typically, the author(s) of the paper will upload a draft version to the preprint server, which generates a publicly accessible URL where the paper and any other relevant data may be viewed, downloaded, or shared. Because the peer review process can often take months or even years, preprints are a quick way to circulate research outputs and data, but authors of preprints seek formal publication after uploading to a preprint server. Preprint servers may be discipline-specific (ex. bioRxiv), regional (ex. AfricArXiv), multidisciplinary (ex. arXiv, SocArXiv), or general purpose (ex. Zenodo). Preprint server is a Casebook value under the "Network Terrain" variable in the code book.