What are these markings ? (2017 ram)

I remember back in the good old days our fun came when the trucks were still carbureted. We would rev them up shut them off pump the accelerator pedal a few times and then just turn the key to the on position which would create a big boom backfire through the tailpipe and scare the HELL out of anyone nearby. It could be heard all over the plant and sometimes that particulator truck would get an identifying mark to change the muffler . Oh the good old days, what the new factory workers are missing.