Often overshadowed by spray painted tags, moniker chalking has a long history in American railroading, going back to the beginning of the Industrial Revolution. Moniker chalking has it's roots in the earliest hobos, itinerant farm workers who hopped freight trains to get from one job to the next. Soon, messages started being scrawled on rail cars, messages about where to be careful and what to expect at the various yards and depots. Along with the important info, the artists began to leave little reminders of themselves, a signature and date, and the tradition was born.
You still see these small tags today, usually in grease pencil or paint pen, and most frequently on older cars. Some of them are years, or even decades old, some of them are still fresh. This happens to be Colossus of Roads, a pretty well known mark. His jaunty cowboy is usually accompanied by a short message-in this case "Summer Complaint-Crimps In Pages". I've no idea what it means, but I like it.