Student eligibility for participation in interscholastic athletics at the high school level shall be based on the following criteria: Students shall be officially registered and attending the member MPSSAA school they are authorized to attend under regulations of the local school system. They may represent only the school in which they are registered and at which it is anticipated they will complete their graduation requirements. Each local school system shall establish standards of participation which assure that students involved in interscholastic athletics are making satisfactory progress toward graduation. Students who are 19 years old or older as of August 31 are ineligible to participate in interscholastic athletics. Students in grades 9, 10, 11, and 12 may participate in interscholastic athletic contests for a maximum of four seasons in any one sport. Middle, intermediate, or junior high school students are not eligible to compete or practice with high school teams. However, ninth grade public school students who reside in the attendance area of a high school organized grades 10—12 may participate in the interscholastic athletic program of that high school. Students shall maintain amateur status as defined by Regulation .10 of this chapter. Students, while participating on a school team, are permitted to participate on sports teams outside of school during the high school sport's season. This participation shall meet the following criteria: The outside participation may not conflict with the practice or contests schedule of the school including district, regional, and State championship play unless prior written approval has been obtained from the school principal and coach; Students who elect to participate on an outside team and do not participate and practice with the school team throughout the designated sport's season are ineligible to represent the school in all contests that determine a county, district, regional, or State championship during that sport season. Students shall present to their high school principal a certificate of permission to participate signed by their parent or parents, or guardian or guardians. Students shall be examined and certified to the high school principal as being physically fit to participate in any try-out, practice, or contest of a school team. The examination shall be performed by a licensed physician, certified physician assistant under the supervision of a licensed physician, or certified nurse practitioner. Students legally transferred to another school may participate. “Legally transferred” means a change of residence or a transfer from one school to another by action approved by the local superintendent of schools. Graduates. Graduates of high schools are not eligible to practice with or participate on interscholastic sports teams. However, they may participate in the remaining athletic contests of that semester. Students are considered graduates when they have completed the work required for graduation and are declared graduates by the local board of education.