Reg can mean short for "regular" or a nickname for "Reggie".
In the UK reg can also mean a motor vehicle "registration number".
VSRL-PASS-REG is Dallas, TX's offense code for driving without current registration in a passenger vehicle. It's the same as driving with expired plates.
It comes from the Latin regere (to rule) or regnare (to reign) or regula (a rule) or another cognate form.
straighten, rule
Registered in 1997/8
I`m pretty sure it means king