There's a really good post on military markings on our blog that you might want to check out:
U.S. Military Jeep Markings - (Military markings for jeep vehicles can sometimes be confusing and difficult to figure out. There are many regulations regarding the markings of military property; however, this post will hopefully provide some assistance in finding appropriate markings for your jeep vehicle).
The AR-850-5 also provides detailed information about U.S. Military Equipment Markings.