http-status-code/json/rfc2817.json

Easy access to HTTP Status Codes

//  Upgrading to TLS Within HTTP/1.1
//  http://tools.ietf.org/html/2817

{
	//  4xx  -  User Error

	//   Reliable, interoperable negotiation of Upgrade features requires an unambiguous failure signal. The
	//  426 Upgrade Required status code allows a server to definitively state the precise protocol
	//  extensions a given resource must be served with.
	"426": "Upgrade Required"
}