Court legal guardians are considered parents in terms of policy. Guardians are adults who have the parents' permission to take a minor to an SCA event. Guardians need to bring a minor waiver form filled out by the parents, which is then turned into the front check in gate. In addition, guardians need to bring a medical treatment form with them to an event, keeping it easily accessible for emergencies. Note that this form does not guarantee medical treatment, just makes it more likely to happen. Given the multitude of countries, states and medical organizations, we can not create anything that would fit all possibilities.
If that minor is 16 or 17 years of age and in youth combat, then the young person should also have a second copy of medical waiver plus the appropriate youth combat paperwork. The guardian must sign the official youth activities permission slip for the minor to participate in official youth activities.
If you agree to be a guardian, you are making a commitment to be responsible for the minor's safety and well being, even if it means giving up your favorite activities.
When going to an event, particularly the larger ones or out of your area it is a good idea to check with the event steward (autocrat) to see if there are any different rules in place.