The Compliance Assessment Toolkit will support the EOSC PID policy with services to encode, record, and query compliance with the policy. To do so, a wide range of compliance requirements ( TRUST, FAIR, PID Policy, Reproducibility, GDPR, Licences) will be evaluated as use cases for definition of a conceptual model. At the same time, vocabularies, concepts, and designs are intended to be re-usable for other compliance needs: TRUST, FAIR, POSI, CARE, Data Commons.