The agreement system includes interline-revenue-sharing management on the valid carrier page and interline revenue sharing administration on the participating carrier page. These United Flight Coupons are valued and invoiced on a pro rata basis in accordance with the special pro rata agreement between Great Lakes and the ticketing airline or, in the absence of an applicable special agreement, in accordance with the ACH Manual of Procedures, depending on its applicability. The Special Prorate Agreement is a special example of an interline agreement that precisely defines the allocation of fees and the invoicing of ticket fees between airlines.