You are viewing the version of this documentation from Perl blead. This is the main development branch of Perl. (git commit e49de0c3a4d0a4f000e7edb2711fab12649ea73b)
@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.