TIdHTTPProtocolVersion is an enumerated type used to represent the HTTP Protocol version for a request. TIdHTTPProtocolVersion can be one of the following values:
pv1_0 - HTTP 1.0
pv1_1 - HTTP 1.1
TIdHTTPProtocolVersion identifies the protocol version that an HTTP server must support in order to respond to the Get, Head, Post, or PostFromStream request.