The CAT can serve as a valuable Knowledge Base for PID Stacks within EOSC, offering comprehensive information, resources, and concrete examples of existing PID stacks (e.g., DOIs, ORCIDs) along with guidelines and best practices for their implementation and management within the EOSC ecosystem, as developed in the FAIR-IMPACT project. As a result CAT could provide new users with easy access to information on PID implementation, management, and compliance, helping them navigate the complexities of the PID landscape, and assisting with selection of appropriate PID stacks for their use cases.