This code system http://hl7.org/fhir/restful-interaction defines the following codes:
| Lvl | Code | Display | Definition |
| 1 | read | read | Read the current state of the resource. |
| 1 | vread | vread | Read the state of a specific version of the resource. |
| 1 | update | update | Update an existing resource by its id (or create it if it is new). |
| 1 | patch | patch | Update an existing resource by posting a set of changes to it. |
| 1 | delete | delete | Delete a resource. |
| 1 | history | history | Retrieve the change history for a particular resource, type of resource, or the entire system. |
| 2 | history-instance | history-instance | Retrieve the change history for a particular resource. |
| 2 | history-type | history-type | Retrieve the change history for all resources of a particular type. |
| 2 | history-system | history-system | Retrieve the change history for all resources on a system. |
| 1 | create | create | Create a new resource with a server assigned id. |
| 1 | search | search | Search a resource type or all resources based on some filter criteria. |
| 2 | search-type | search-type | Search all resources of the specified type based on some filter criteria. |
| 2 | search-system | search-system | Search all resources based on some filter criteria. |
| 1 | capabilities | capabilities | Get a Capability Statement for the system. |
| 1 | transaction | transaction | Update, create or delete a set of resources as a single transaction. |
| 1 | batch | batch | perform a set of a separate interactions in a single http operation |
| 1 | operation | operation | Perform an operation as defined by an OperationDefinition. |