 Two notable exceptions were Lexington and Warrensburg, which were included in 660 even though they are generally considered as part of the Kansas City area.On June 4, 1997, the Missouri PSC announced that 660 would begin its split on October 12, 1997.On that date, a permissive dialing period began during which long-distance calls to the 660 territory could be completed using either 816 or 660.