This code system http://hl7.org/fhir/restful-interaction defines the following codes:

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.
<status value="active"/> <experimental value="false"/> <publisher value="FHIR Project"/> <description value="The set of interactions defined by the RESTful part of the FHIR specification."/> <jurisdiction> <coding> <system value="http://unstats.un.org/unsd/methods/m49/m49.htm"/> <code value="001"/> <display value="World"/> </coding> </jurisdiction> <caseSensitive value="true"/> <valueSet value="http://hl7.org/fhir/ValueSet/restful-interaction"/> <hierarchyMeaning value="is-a"/> <content value="complete"/> <concept> <code value="read"/> <display value="read"/> <definition value="Read the current state of the resource."/> </concept> <concept> <code value="vread"/> <display value="vread"/> <definition value="Read the state of a specific version of the resource."/> </concept> <concept> <code value="update"/> <display value="update"/> <definition value="Update an existing resource by its id (or create it if it is new)."/> </concept> <concept> <code value="patch"/> <display value="patch"/> <definition value="Update an existing resource by posting a set of changes to it."/> </concept> <concept> <code value="delete"/> <display value="delete"/> <definition value="Delete a resource."/> </concept> <concept> <code value="history"/> <display value="history"/> <definition value="Retrieve the change history for a particular resource, type of resource, or the entire system."/> <concept> <code value="history-instance"/> <display value="history-instance"/> <definition value="Retrieve the change history for a particular resource."/> </concept> <concept> <code value="history-type"/> <display value="history-type"/> <definition value="Retrieve the change history for all resources of a particular type."/> </concept> <concept> <code value="history-system"/> <display value="history-system"/> <definition value="Retrieve the change history for all resources on a system."/> </concept> </concept> <concept> <code value="create"/> <display value="create"/> <definition value="Create a new resource with a server assigned id."/> </concept> <concept> <code value="search"/> <display value="search"/> <definition value="Search a resource type or all resources based on some filter criteria."/> <concept> <code value="search-type"/> <display value="search-type"/> <definition value="Search all resources of the specified type based on some filter criteria."/> </concept> <concept> <code value="search-system"/> <display value="search-system"/> <definition value="Search all resources based on some filter criteria."/> </concept> <concept> <code value="search-compartment"/> <display value="search-compartment"/> <definition value="Search resources in a compartment based on some filter criteria."/> </concept> </concept> <concept> <code value="capabilities"/> <display value="capabilities"/> <definition value="Get a Capability Statement for the system."/> </concept> <concept> <code value="transaction"/> <display value="transaction"/> <definition value="Update, create or delete a set of resources as a single transaction."/> </concept> <concept> <code value="batch"/> <display value="batch"/> <definition value="perform a set of a separate interactions in a single http operation"/> </concept> <concept> <code value="operation"/> <display value="operation"/> <definition value="Perform an operation as defined by an OperationDefinition."/> </concept> </CodeSystem>