The EOSC EU Node (EEN) Resource Catalogue is designed to offer discovery and access to the map of resources made available in the EOSC Federation via the EOSC Nodes, including the EEN itself. In particular, it aggregates research product profiles (publications, research data, research software) collected from the research product catalogues of EOSC Nodes. The resulting Catalogue is accessible via the EOSC Resource Hub discovery portal (and open APIs), and can be used to discover, access, and monitor EOSC research products across the EOSC Nodes in the Federation. This document outlines the EOSC Resource Catalogue interoperability guidelines that EOSC Node Research Product Catalogue providers should follow to register their catalogues with the EEN Resource Catalogue, making their research products discoverable, visible, and accessible beyond their Node’s boundaries.