I came across an unusual signal while railfanning, and as I've been studying the different signal aspects and indications used by railroads, does anyone know what a "ds" plate mounted on a signal mast underneath the signal head means? I know an "G" or "R" plate upgrades a stop indication to restricting, and number plate makes the signal permissive (usually, depending on the road). I think it might be a variant of the "D" plate that means the signal is a distant signal but I'm not sure. Sorry I don't have a picture, my camera's battery had died, and I couldn't find any pictures online.
Under NORAC, DS was used for switch closed/switch open signals.
It indicated either to proceed, or proceed prepared to stop short of open switch.
It's been fun. But it isn't much fun anymore. Signing off for now.
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.t fun any