Urbano, CristóbalRozemblum, CeciliaBanzato, Guillermo2026-02-182026-02-182026-02-120022-0418https://hdl.handle.net/2445/227008PurposeTo analyse the clarity of Spanish academic journals' preprint acceptance policies in their instructions to authors, to assess which journals have adopted explicit policies on preprints and how these policies align with the transparency recommendations of the Committee on Publication EthicsDesign/methodology/approachAn analysis was conducted of the preprint acceptance policies of 221 Spanish academic journals classified in the Q1 and Q2 quartiles of the Scimago Journal & Country Rank. The instructions to authors and self-archiving policies on the journals' websites were examined, as well as the Open Policy Finder and Dulcinea directories. The journals were classified into four categories: explicit acceptance, explicit rejection, unclear mention and no mention.FindingsOnly 17.6% of the journals analysed clearly state their preprint policy (15.4% explicitly accepting preprints and 2.3% explicitly rejecting them), while 40.3% make confusing statements and 42.1% make no mention of preprints. So that, there is significant room for improvement in the way journals present their preprint policies.Research limitations/implicationsTo ensure the feasibility of our work, not all Spanish academic journals were considered, many of which are not even included in Scopus. This limitation was accepted in the study, as we wanted to focus on those titles that were better positioned in an international context, even though this prevented us from extrapolating the results to all Spanish journals.Originality/valueThis study is one of the first to explore the preprint policies of scientific journals based on analysis of instructions to authors. Although the sample corresponds to Spanish journals, the results may be useful at the international level. The results have twofold value: they show that preprints, as an important component of open science, are not the focus of attention of Spanish open access journals; on the other hand, the paper prompts self-assessment for publishers to improve the clarity of instructions to authors.21 p.application/pdfeng(c) Emerald Publishing, 2026Accés obertCiència obertaEdició electrònicaOpen access publishingOpen scienceElectronic publishinginfo:eu-repo/semantics/article7653162026-02-18info:eu-repo/semantics/openAccess