///\r
#define HTTP_HEADER_IF_NONE_MATCH "If-None-Match"\r
\r
+///\r
+/// The WWW-Authenticate Response Header\r
+/// If a server receives a request for an access-protected object, and an\r
+/// acceptable Authorization header is not sent, the server responds with\r
+/// a "401 Unauthorized" status code, and a WWW-Authenticate header.\r
+///\r
+#define HTTP_HEADER_WWW_AUTHENTICATE "WWW-Authenticate"\r
+\r
///\r
/// Authorization Request Header\r
/// The Authorization field value consists of credentials\r