Project Summary/Abstract The Brain Imaging Data Structure (BIDS) is a BRAIN initiative (R24 MH114705) community-driven standard meant to maximize neuroimaging data sharing, and facilitate analysis tool development. We propose to extend the standard to encompass derivatives resulting from experiments related to both functional as well as structural magnetic resonance imaging data that describe macroscopic brain connectivity estimates. The focus of this proposal is to advance BIDS to describe the entire experimental workflow—from minimally processed anatomical, functional and diffusion MRI data through connectivity matrices and tractometry features—in service of supporting BRAIN initiative studies of large-scale connectivity of human and nonhuman brains. BIDS was initially scoped to MRI data of the brain, but the standard has set up a solid infrastructure to steer the community and has been extended to cover a range of other modalities (PET, EEG, MEG, ECoG). Since its first announcement, BIDS has evolved to become an organized community with shared governance and a strong impact well beyond the U.S. BRAIN initiative. To date, 131 individuals among faculty, students, and postdocs contributed to the development of the standard and the article describing BIDS has been cited 277 times. Current gaps exist in developing BIDS to effectively support the process of scientific results generation. This is because the standard does not yet describe brain features that can be extracted from MRI data and that are routinely used to perform statistical tests and complete scientific studies. These features comprise connectivity maps, structural and functional connections, major white matter tracts, diffusion signal models as well as white matter tractograms and tractometry. Sharing processed data and features in addition to raw and minimally-processed data is critical to accelerating scientific discovery. This is because substantial effort, software, and hardware instrumentation, and know-how are required to bring raw data to a usable state. One previous project (R24 MH114705) laid the foundations for the BIDS derivatives standard, ultimately leading to the existing Common Derivatives standard. However, the current BIDS derivative standard does not cover advanced data derivatives that describe brain connectivity experiments. The current proposal is to advance the BIDS standard beyond preprocessed data to describe data products generated from experiments and models fit after preprocessing. The project will deliver a community-developed standard describing brain connectivity experiments. The standard will be accompanied by software to validate the datasets.