The term fan marker refers to the older type of beacons used mostly for en-route navigation.[5][6] Fan-type marker beacons were sometimes part of a non-precision approach and are identified by a flashing white light and a repeating dot-dash-dot signal.[7] Recent editions of the FAA's AIM publication no longer mention fan markers.[4][8] In August 2017 seven fan markers remain in service in the USA. [citation needed]