A blue flag displayed at one or both ends of equipment indicates that workers are in the vicinity of such equipment.
When such signals are displayed the equipment must not be coupled to or moved.
The removal of the blue flag from one or both ends of the equipment shall indicate that workers are no longer in the vicinity and such equipment may be coupled to or moved.
Only the same class of workers who put up the blue flag can remove the flag.
Peter Haines
Secretary Treasurer