Upon receipt of notification from the Department that a school's habitual truancy rate exceeds the standard specified in §B of this regulation, the local school superintendent or the superintendent's designee shall direct the principal of the school to implement: A PBIS; or An alternative behavior modification program developed in collaboration with the Department. A school is subject to this regulation if it has a truancy rate that exceeds: 8 percent of its enrollment for the 2008—2009 school year; 6 percent of its enrollment for the 2009—2010 school year; 4 percent of its enrollment for the 2010—2011 school year; 2 percent of its enrollment for the 2011—2012 school year; and 1 percent of its enrollment for the 2012—2013 school year and each school year thereafter. The school principal or the principal's designee and appropriate staff members shall: Develop a plan for implementing a program as set forth in §A of this regulation; Attend PBIS or alternative behavior modification training program approved by the Department; and Follow implementation guidelines and practices for PBIS or the alternative behavior modification training program. A school shall expand its existing PBIS or alternative behavior modification program by providing more intensive interventions to targeted students in need of such interventions if: The school has already implemented a PBIS or an alternative behavior modification program; and The school has a truancy rate that exceeds the standard specified in §B of this regulation. Nothing in this regulation precludes a school system from implementing PBIS or an alternative behavioral modification program either in specific schools or system-wide.