Jquery Validation for confirm serial

Question

I have this code in Jquery for confirmation of not re-entering same Serial
Rule that needs to be follow is:
1. Required filled(done)
2.minLength 5 (done)
3.cant input same serial if serial is already inputted in other textbox(missing validation)

jQuery('.validatedForm').validate({
    rules: {
     while (serialGeneratedQuantity < 10) {
           serialGeneratedQuantity++;
           serial+serialGeneratedQuantity: {
            required: true,
            minlength: 5
            },
       }
    }
});