Inrun Markers
From FIS Freestyle wiki

Inrun Markers are needed at two-meter intervals, must be placed on the side of the inrun, in a straight line ending approximately 20 meters above the transition.
two-meter intervals, must be placed on the side of the inrun, in a straight line ending approximately 20 meters above the transition.
Also See
Return to 4002, Aerial Course Specification, Freestyle Equipment List, Freestyle Skiing or Competition Organization