You are viewing the version of this documentation from Perl blead. This is the main development branch of Perl. (git commit 8525a10c5f15cf09a75976adf6f633815f2b49c6)
@ARG
@_

Within a subroutine the array @_ contains the parameters passed to that subroutine. Inside a subroutine, @_ is the default array for the array operators pop and shift.

See perlsub.