Limnology and Oceanography Letters was conceived as a fully open science journal where all articles and their underlying data are freely available online (Soranno et al. 2021). The data publication requirement, described in the author guidelines (https://aslopubs.onlinelibrary.wiley.com/hub/journal/23782242/about/author-guidelines#data), ensures that the data set(s) analyzed in each study, and the metadata describing them, are easily accessible to support the authors' conclusions. This requirement is a journal commitment to the FAIR principles of improving Findability, Accessibility, Interoperability, and Reuse of scientific data (Wilkinson et al. 2016). Data publication benefits authors by fostering reproducibility, enhancing the credibility of your results, and increasing the likelihood that your paper will be cited (Christensen et al. 2019). Although the journal's online author guidelines explain the data-publication requirement, we receive submissions where that requirement is not fully met. Those submissions are returned unreviewed to authors, delaying the editorial process. As a guide for authors, I provide here a checklist of the five steps taken at the editorial office to verify that the data-publication requirements are fully met so your paper can be forwarded for review. 1. Have the authors published their data and metadata in a freely accessible repository with a permanent identifier and a URL for accessing both? Authors are required to publish the data file(s) they analyzed with metadata in a publicly accessible repository that issues a new DOI, including unique identifiers and other critical identifying components. Founding Editor Patricia Soranno provides a step-by-step guide for publishing data to meet this requirement (Soranno 2019). The published data can be embargoed during the review process, but the embargo must be removed once an article is accepted for publication. To be clear, the journal's requirement is not met by placing your data in supplementary material, by making data available on request, or by citing the DOI of a larger data set from which the analyzed data were extracted. Most data sets analyzed in this journal are built from original data produced by the authors, subsets of published data, merging data from multiple sources, and/or manipulating data. The intent is transparency and reproducibility of your work by requiring direct access to the exact version of data you created, compiled, and analyzed to support your conclusions. You can include ancillary data if they are given an identifier to distinguish them from the data you analyzed. The one exception to the data-publication requirement is for unusually large data sets that exceed the repository's maximum limit. In these cases, you can meet the requirement by publishing the code written to produce the data file(s) analyzed in your article. 2. If data and metadata have not been published before submission, do the authors provide a plan for meeting this requirement? The journal's policy allows authors to publish their data while their manuscript is under review. If your data have not been published at the time of manuscript submission, you will be asked to specify the repository where your data will be published and to include in your submission a metadata file following the L&O Letters Metadata Template (available in author guidelines). Submission of a metadata file is not necessary if you intend to publish your data in a repository that requires comprehensive documentation and metadata comparable to that in the L&O Letters Template (e.g., EDI, Zenodo, BCO-DMO, Pangea, and ScienceBase). In this case, you can simply provide the general URL to the data repository. 3. Have the authors included a Data Availability Statement? Authors must include a Data Availability Statement in their manuscript, just after the Author Contribution Statement. For an original submission where your data have not yet been published, insert the statement: (Data and metadata will be made available in the XXX data repository). For a revision, insert the statement: (Data and metadata are available at [insert the URL where your data are available]). 4. For a revised manuscript, do the authors provide the URL link for the published data that includes the metadata file? Revised manuscripts will be reviewed only after the data publication requirement is met, including publication of both data and metadata. 5. Do authors cite their data publication? Authors must include a citation of their data publication in the References section of their manuscript and cite this publication in the main body of the text (typically in Methods section). This step is essential for tracking the use of data sets and to ensure that data producers receive credit for their work as a citation.