http://www.rfc-editor.org/rfc/rfc7838.txt
RFC 7838: HTTP Alternative Services, M. Nottingham, P. McManus, J. Reschke2016-04-01T23:00:00-00:00This document specifies "Alternative Services" for HTTP, which allow an origin's resources to be authoritatively available at a separate network location, possibly accessed with a different protocol configuration.