| Code | Display | Definition |
| realm-base | Realm Base | Defines use-case independent foundational expectations for exchange within a particular country or jurisdiction. Should be accompanied by a jurisdiction. Commonly used as a 'base' for more restrictive artifacts. |
| knowledge | Knowledge | Defines use-case-specific information or guidance that is relevant to a specific business or health domain but is not mandated for particular use. |
| domain | Domain | Defines use-case-specific requirements for a specific business or health domain. May vary in jurisdictional scope from international to small region and in business scope from broad to narrow. |
| community | Community | Sets contractual or business expectations for systems participating in a particular exchange community. |
| system-design | System Design | Documents the specific capabilities of a single system as 'available' for purchase or use. May have some variability reflecting options that can be configured. |
| system-implementation | System Implementation | Documents the specific points of a single production system or endpoint. This may be time-specific - i.e. reflecting the system 'as it is now' or 'as it was at some point in the past'. |