=over

=item HANDLE->format_name(EXPR)

=item $FORMAT_NAME

=item $~
X<$~> X<$FORMAT_NAME>

The name of the current report format for the currently selected
output channel. The default format name is the same as the filehandle
name. For example, the default format name for the C<STDOUT>
filehandle is just C<STDOUT>.

Mnemonic: brother to C<$^>.

=back