Once you get into repainting or fixing up rolling stock, Microscale decals tend to come up pretty quickly when you're looking for lettering and markings for sale. They’re what most people use when they want something to actually match a real railroad instead of just getting close.
From road names and numbers to small warning labels and logos, the detail is what makes the difference when finishing a model. You can find more in model trains when putting together a complete and consistent roster.