HEAD. While the
HEADoperation has no message body per the HTTP specification, the
GEToperation is not supported in ARC because all web clients don't support it. The
GEToperation should not carry the body.
Content-Typeheader in the headers editor. When you switch the value in the mime type selector, then the header value is updated. This also works the other way around. When the Content-Type header value changes in the editor the body editor will start using it for syntax highlighting.
www-url-form-encodedvalues, you can use the URL from-enoded editor to build the message. It renders a form of parameters and takes care of the final formatting of the message.