The only things on the warning sign that aren't personal choices are height and weight restrictions. In order to ride the roller coaster, you must be a minimum height. In some cases, there is a weight minimum and maximum to ride certain coasters. Some rides have two different height restrictions, one for riding alone and another height allowing a child to ride, but only with an adult accompanying him.
Roller coasters have a listing of warnings based on health conditions that can be aggravated by riding the attraction. Some health warnings on these signs include high blood pressure, heart disease or a heart condition. Many roller coasters don't allow those who are pregnant to ride the attraction for the safety of both the mother and child. The signs also warn against those who suffer from neck or back issues or motion sickness.
You will find instructions on how to sit, stand or position yourself on the ride. Warnings on how to sit are also verbally communicated by the employee or recording as guests are strapped in and verified by other employees. You will be instructed to remain seated and keep your hands inside the ride at all times, which pertains to not putting your hands on the outside of the vehicle or near the tracks of the roller coaster. On most rides, it is safe to raise your hands over your head when during the ride and you will be instructed otherwise if it is not. Failure to follow these warnings can result in being asked to leave the ride and possibly being injured while not following the rules of the ride.
Some rides can scare the faint at heart or younger riders and these warnings are placed on signs outside of the ride's entrance. Personal phobias that may be encountered when riding a roller coaster include darkness, frightening situations or fear of heights. If you or anyone in your party suffers from these phobias, either don't ride the roller coaster or be prepared to be scared.