You are viewing the version of this documentation from Perl blead. This is the main development branch of Perl. (git commit 55c5b505cb6ecaf868f1326432801de3a67c9943)
@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.