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

CodeDefinition
GET HTTP GET Command.
HEAD HTTP HEAD Command.
POST HTTP POST Command.
PUT HTTP PUT Command.
DELETE HTTP DELETE Command.
PATCH HTTP PATCH Command.
<status value="active"/><experimental value="false"/><date value="2021-01-05T10:01:24+11:00"/><publisher value="HL7 (FHIR Project)"/><contact><telecom><system value="url"/><value value="http://hl7.org/fhir"/></telecom><telecom><system value="email"/><value value="fhir@lists.hl7.org"/></telecom></contact><description value="HTTP verbs (in the HTTP command line). See [HTTP rfc](https://tools.ietf.org/html/rfc7231) for details."/><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/http-verb"/><content value="complete"/><concept><code value="GET"/><display value="GET"/><definition value="HTTP GET Command."/></concept><concept><code value="HEAD"/><display value="HEAD"/><definition value="HTTP HEAD Command."/></concept><concept><code value="POST"/><display value="POST"/><definition value="HTTP POST Command."/></concept><concept><code value="PUT"/><display value="PUT"/><definition value="HTTP PUT Command."/></concept><concept><code value="DELETE"/><display value="DELETE"/><definition value="HTTP DELETE Command."/></concept><concept><code value="PATCH"/><display value="PATCH"/><definition value="HTTP PATCH Command."/></concept></CodeSystem>