I. The term "high school'' shall mean a public school or public academy comprising a span of grades beginning with the next grade following an approved elementary, middle or junior high school as defined by RSA 189:25 and ending with grade 12. Such a school shall: (a) Offer those subjects prescribed by statute, including instruction in history, government, and constitutions of the United States and New Hampshire and of the organization and operation of New Hampshire municipal, county, and state government; (b) Provide such other subjects as the school district maintaining such school shall determine by its school board or by vote of the district; (c) Comply with standards prescribed by the state board of education which shall be uniform in their application to all schools; and (d) Qualify a pupil to receive a diploma upon completion. II. In this section, "public academy'' means an independent school which contracts with one or more school districts to provide education services to such districts in compliance with RSA 194:23. All contracts between a public academy and a school district shall be subject to approval by the state board of education. In this section, "independent school'' means a school which is governed by a board of trustees or other officials who are not publicly elected. An independent school shall not include a chartered public school established under RSA 194-B. III. The enactment of paragraph II shall not affect a determination of the New Hampshire retirement system board of trustees under RSA 100-A regarding the eligibility of an employer or its employees to participate in the New Hampshire retirement system.