This code system http://hl7.org/fhir/action-relationship-type defines the following codes:
| Code | Display | Definition |
| before-start | Before Start | The action must be performed before the start of the related action |
| before | Before | The action must be performed before the related action |
| before-end | Before End | The action must be performed before the end of the related action |
| concurrent-with-start | Concurrent With Start | The action must be performed concurrent with the start of the related action |
| concurrent | Concurrent | The action must be performed concurrent with the related action |
| concurrent-with-end | Concurrent With End | The action must be performed concurrent with the end of the related action |
| after-start | After Start | The action must be performed after the start of the related action |
| after | After | The action must be performed after the related action |
| after-end | After End | The action must be performed after the end of the related action |