I am a historian and I love studying both the Roman Army (Exercitus Romanorum)--i.e.,the legions--and the armies of the many independent Greek city states. A Roman legion was formed from 10 COHORS "cohorts," each Cohors being 6 CENTURIAE "centuries" (except the 1st Cohort, which had double centuries); the century in turn, was formed from the basic 8-man tent group known as a CONTUBURNIUM. Ten contuburnia formed 1 century (about 80 men). All the Greek armies, on the other hand, fought primarily in the more inflexible (but heavy shock power) infantry formation known as a "phalanx" (with cavalry in support); basic equipment was a helmet, a sword, a very long spear, and a round, convex shield called a "hoplon"--from which the name of Greek infantry soldiers (regardless of which city state) was derived: "HOPLITE".
I thought this vanity plate was especially cool, since this person clearly knew his ancient history! The pickup bearing the plate was parked on an Army base--what do you want to bet, that the owner is an infantryman--a modern day HOPLITE, so to speak?