A warning line system is a safety setup used on rooftops or elevated work areas to mark safe boundaries and alert workers to potential fall hazards. Consisting of highly visible flags or markers attached to ropes or wires, this system creates a clear visual perimeter around hazardous zones. Often used in construction and roofing, a warning line system helps guide workers safely, preventing accidental entry into unsafe areas. Though it doesn't physically prevent falls, it's an essential part of fall prevention protocols and compliance with safety regulations in many work environments.