The EHDEN project aims to make healthcare data in Europe Findable, Accessible, Interoperable and Reusable (FAIR) at an unprecedented level. This deliverable explores what this entails technically, and how the technical framework of EHDEN, including the OMOP model and the EHDEN Portal, could maximize the FAIRness of its data artefacts and their interoperability. It does so by delineating digital objects defined and exchanged in the context of EHDEN and OHDSI, such as model versions, vocabulary versions, database profiles, cohort definitions, query definitions, query results, analytics packages, study protocols, study results, as well as publications, authors, organizations, projects, studies, study-a-thons etc. The deliverable also goes into related biomedical data standards and communities that exist and how they relate to each other. The EHDEN project has explicitly chosen to standardize healthcare data for analysis using the OMOP Common Data Model, but other interoperability solutions, such as i2b2, CDISC, FHIR, openEHR, GA4GH etc. also play an important role. This document addresses the relevance of those standards for the data (re)use goals of EHDEN, and points out how OMOP and OHDSI relate to them.