Since message parsing (Section 6 of [Messaging]) needs to be
independent of method semantics (aside from responses to HEAD),
definitions of new methods cannot change the parsing algorithm or
prohibit the presence of a message body on either the request or the
response message. Definitions of new methods can specify that only a
zero-length message body is allowed by requiring a Content-Length
header field with a value of "0".
The spec says:
but https://tools.ietf.org/html/draft-ietf-httpbis-semantics-11#section-8.4.2 says
You might get a question from the HTTP police.