The repository supports most file formats but, when possible, datasets should be saved in file formats that support long-term preservation. Those formats differ by data type but generally include non-proprietary, open formats. Tabular datasets in some CSV, Excel, R, SPSS, and Stata formats are automatically converted into a tab-separated format upon ingest.

Individual files and compressed folders can be up to 5 GB in size. Multiple files may be included in a dataset.

Files should be named clearly and consistently without spaces or special characters. Multiple files may be organized into hierarchical folders.