OPINION — AG — RULE NO. 13 OF THE "STATE BOARD OF EDUCATION REGULATIONS FOR ADMINISTRATION AND HANDBOOK ON BUDGETING AND BUSINESS MANAGEMENT", BULLETIN NO. 145-S, 1977-78, PROVIDING FOR THE GRANTING OF OUTSIDE EXPERIENCE CREDIT IF ONE, AT THE TIME OF SUCH PRIOR AND OUTSIDE TEACHING EXPERIENCE, WAS OTHERWISE ELIGIBLE TO HAVE OBTAINED A TEACHING CERTIFICATE, IS NOT UNCONSTITUTIONAL UNDER THE EQUAL PROTECTION CLAUSE OF THE FOURTEENTH AMENDMENT TO THE UNITED STATES CONSTITUTION NOR UNDER THE APPLICABLE STATE LAW. CLASSIFICATIONS, FOR TEACHING EXPERIENCE CREDIT PURPOSE, BASED, IN PART, UPON PREPARATORY EDUCATION, TRAINING AND EXPERIENCE, ARE CONSTITUTIONALLY PERMISSIBLE. CITE: 70 O.S. 1977 Supp., 18-114 [70-18-114], 70 O.S. 1977 Supp., 3-104 [70-3-104] (R. THOMAS LAY)