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