100's Manifest/Mixed trains
200-270 Intermodal trains
270-299 Auto trains
300-400 Mixed trains
500-600-700 Some coal, also ore, stone, and other bulk commodities
900 light engine moves/special work, I believe
In theory, eastbounds have even numbers and westbounds odd, not sure about north/south.
When NS added Conrail's trains back in '99, they ran out of 3 digit #'s so they started using 13 letters of the alphabet to replace the final number of certain trains.
For example, NS train 145 passes westbound thru Fostoria, Ohio each day.
So does eastbound coal train 84M. This train is an 840 series coal train.
There's lots more but that's a start.