# ***  Incorrect  ****
if ( @{$Tape_Cat{ $label}} < 2 ) {
  # Executes if there is only 1 (or 0) instances of $label
}


# ***  Correct  ***
if ( @{$Tape_Cat{ $label}} > 1 ) {
  # Executes if there is more than 1 (ie, any duplicates)
}