Canadian Rail Operating Rules
The Canadian Rail Operating Rules are intended to enhance railway safety.The rules cover employee responsibilities, signalling equipment, procedures for safe train movement, dealing with accidents and other topics that directly and indirectly affect railway safety.A "DV" plate makes a slow-speed signal into diverging speed.If they are not absolute, the signal is controlled by CTC, and the crew may go at restricted speed after a complete stop.[4] (An L plate on the signal mast makes any medium-speed indication a limited-speed upgrade) (A slow-speed indication becomes diverging speed if the mast has a DV plate)