Speaking of zerocal, have you ever noticed that low calorie packaged foods like pickles and cauliflower will put tiny serving sizes on the package so they can advertise 0 calories? I think they round down to zero when it's less than 5 calories.
Yep. Another suspect of this is cooking oil spray, like Pam. They can advertise very low calories, usually 0, per serving but a serving is considered like 1/3 of a second spray.