Issue #22091 has been reported by cryptogopher (crypto gopher). ---------------------------------------- Misc #22091: Missing Regexp documentation on relative (negative) backreferences https://bugs.ruby-lang.org/issues/22091 * Author: cryptogopher (crypto gopher) * Status: Open ---------------------------------------- I found out about them elsewhere: https://idiosyncratic-ruby.com/11-regular-extremism.html#relative-back-refer.... Description below is sourced from blog linked above: Relative Back-References Back-refs can be relatively referenced from the current position via \k<-n>: "Ruby by"[/(R)(u)(by) \k<-1>/] #=> "Ruby by" -- https://bugs.ruby-lang.org/