You are viewing the version of this documentation from Perl blead. This is the main development branch of Perl. (git commit e5694b9e05a3e5427ca966f0a7d0dc60b5519e62)
${^UTF8LOCALE}

This variable indicates whether a UTF-8 locale was detected by perl at startup. This information is used by perl when it's in adjust-utf8ness-to-locale mode (as when run with the -CL command-line switch); see perlrun for more info on this.

This variable was added in Perl v5.8.8.