I only use careful as a pre-whoa. If the dog is locked on point and not tring to reset or chase a bird. If he starts to creep up a little bit, I will give a "careful", * When I go to flush, I give a "whoa", meaning to stay put no matter what until he is released... If he refuses my "whoa" he is nicked. I dont nick for ignoring my careful, its really more of just a reminder than a command, whoa is a command though.