A friend of mine is a manager at SBB in Switzerland and says the more experienced (Professional) Graffiti artists know not to spray over the wagon data, this is so the wagon doesn't need to go for immediate repaint, therefor their work can be on display for longer.
![2018-04 [HD] Bahnhof Olten on the platform 2 of 3, Inter. Cargo, Re 6/6 nose job, Twindexx...](http://i.ytimg.com/vi/AEH8AdSYsMA/mqdefault.jpg)
Graffiti seems to be becoming increasingly common on Swiss trains *shakes head disapprovingly*
A friend of mine is a manager at SBB in Switzerland and says the more experienced (Professional) Graffiti artists know not to spray over the wagon data, this is so the wagon doesn't need to go for immediate repaint, therefor their work can be on display for longer.