You might get the train symbol/ID by listening to a scanner if the train is setting out or picking up cars at a yard. But if you are out on the mainline between yards, you will not hear much radio chatter about the train, unless it is given special instructions (slow orders, etc.) and they happen to get identified by both the leading engine number and the train ID (which I have only heard maybe once or twice in 10 years... Usually it is only the leading engine number around here where I listen to the U.P. dishbasher.)
But for identifying the train in a video or such, just use the leading engine number and the location, date/time and direction. Most people would have no idea what the "Symbol" of the train means anyway.
