$string = "2|3||";

print "Backwhacked bar in pattern: ";
print "($_)" for split /\|/, $string; print "\n";
print "Backwhacked bar in quotes:  ";
print "($_)" for split '\|', $string;  print "\n";
print "Just a bar in pattern:      ";
print "($_)" for split /|/, $string;  print "\n";
print "Just a bar in quotes:       ";
print "($_)" for split '|', $string;  print "\n";
__END__
Backwhacked bar in pattern: (2)(3)
Backwhacked bar in quotes:  (2)(3)
Just a bar in pattern:      (2)(|)(3)(|)(|)
Just a bar in quotes:       (2)(|)(3)(|)(|)