But everywhere this occurs, whether it's user code calling http.StatusText, or http.ServeFile when a client requests a bad range, Go gives the client 416 Requested Range Not Satisfiable when the canonical text is 416 Range Not Satisfiable.
Obviously http.StatusRequestedRangeNotSatisfiable will have to stay to avoid breaking compatibility, but:
Of the 14 surveyed popular/critical internet infrastructure, only 3 use that newer RFC's definition -> 21.43%
Given that that might be a sudden change that hasn't been propagated to majority of the surveyed infrastructure as per above, I don't think we should make this change. Despite it being low-risk and not necessarily under the Go1 compatibility promise as it is a status message so amenable, by Hyrum's law, a change (moreover after 11+ years) is bound to break code for someone, and no report has come in in the past 6+ years since its introduction. I thus vote to say let's not change this, but definitely a consideration for Go2, which will give enough time perhaps for maturity of that RFC and adoption by others too.