providing for definitions and construction and providing for references; in retirement membership, contributions and benefits, further providing for mandatory and optional membership, credited school service, waiver of adjustments, providing for spouses rights and benefits and further providing for classes of service, elections, eligibility points, eligibility for annuities, eligibility for refunds, pickup contributions, member contributions, contributions to for purchase of credit, incomplete payments, annual compensation limit, contributions by Commonwealth, payments by employers, actuarial cost method, appropriations by Commonwealth, return of accumulated deductions, maxim single life annuity disability annuities, termination of annuities, various supplemental annuities and payment of benefits; providing for school employees' defined contribution plan; in administrative and miscellaneous provisions, further providing for the Public School Employees' Retirement Board, administrative duties of board, health insurance, advisory and reporting duties, application and election duties, duties of employers, rights and duties of school employees and members, management of fund and accounts, Public School Employees' Retirement Fund, State accumulation account, annuity reserve account, State guarantee, taxation, attachment and assignment of funds, approval of domestic relations orders, irrevocable survivor annuitant and amendment of approved domestic relations orders, providing for irrevocable successor payee, further providing for fraud and adjustment of errors, providing for spousal consent and further providing for payments to school entities by Commonwealth; in health insurance for retired school employees, further providing for definitions; and, in military leave of absence, further providing for retirement rights