Don't check for undefined matches
$1='129'                $2='-'
$1='129A'               $2='&'
$1='B'                  $2='-'
Use of uninitialized value in concatenation (.) or string at test.pl line 8.
$1='131'                $2=''
Use of uninitialized value in concatenation (.) or string at test.pl line 8.
$1='NORTH'              $2=''

Check for undefined matches
$1='129'                $2='-'
$1='129A'               $2='&'
$1='B'                  $2='-'
$1='131'                $2='undef'
$1='NORTH'              $2='undef'

Pseudo Split
'129',
'-',
'129A',
'&',
'B',
'-',
'131',
'undef',
'NORTH',
'undef',
'AV',