The Continua Design Guidelines (CDG) defines a framework of underlying standards and criteria that ensure the interoperability of devices and data used for personal connected health services. Recommendation ITU-T H.812 contains an overview of the Services interface (Services-IF), common design guidelines for all Services-IF Certified Capability Classes (CCC) and the design guidelines for Consent Enabled Personal Health Gateway (PHG) and Services CCCs. The design guidelines which support the following Certified Capability Classes (CCC) are defined in separate Recommendations, as follows: - Observation Upload capability in [ITU-T H.812.1] - Questionnaires capability in [ITU-T H.812.2] - Capability Exchange capability in [ITU-T H.812.3] - Authenticated Persistent Session capability in [ITU-T H.812.4] Recommendation ITU-T H.812 is part of the "ITU-T H.810 interoperability design guidelines for personal connected health systems" subseries that covers the following areas: - ITU-T H.810 - Interoperability design guidelines for personal connected health systems: System overview - ITU-T H.811 - Interoperability design guidelines for personal connected health systems: Personal Health Devices interface design guidelines - ITU-T H.812 - Interoperability design guidelines for personal connected health systems: Services interface design guidelines - ITU-T H.812.1 - Interoperability design guidelines for personal connected health systems: Services interface: Observation Upload capability - ITU-T H.812.2 - Interoperability design guidelines for personal connected health systems: Services interface: Questionnaires capability - ITU-T H.812.3 - Interoperability design guidelines for personal connected health systems: Services interface: Capability Exchange capability - ITU-T H.812.4 - Interoperability design guidelines for personal connected health systems: Services interface: Authenticated Persistent Session capability - ITU-T H.813 - Interoperability design guidelines for personal connected health systems: Healthcare Information System interface design guidelines