Task 5.4 in FAIR-IMPACT had the objective of developing guidelines in respect of the sharing of repository attributes for a number of purposes, including sharing information on the characteristics of a repository, assisting end users with selection of repositories, or validation of such repository attributes. A special focus of this general set of guidelines were exposure of FAIR attributes of trustworthy repositories. Claims in respect of trustworthiness of a repository and its certification as such, and of FAIR compliance in respect of the objects available from a repository (aggregated to reflect the status of FAIR in the repository) are used as examples throughout the report. These are important examples of repository attributes that may require validation, but certainly not the only ones. One can validate the claims in a number of ways, but this is not in scope for the report: we are concerned with the simplest and most expedient way in which such an attribute can be exposed to machines. While this is not the primary focus of the report, a subtitle was included in naming this deliverable to clearly mark and communicate the extra content and recommendations provided to existing and aspiring trustworthy digital repositories (TDRs) with regards to implementing and exposing trustworthiness status.