Are you looking for a symbol, er, star?

Are you looking for a symbol, er, star?

 Was there something other than a star on the hood of WW2 vehicles? You can trust the old WW2 Army Motors to give us an answer!
May 1944, Army Motors:

If you see some peculiar white shapes riding around on vehicles in your vicinity—don’t shoot, they’re not enemy ski-troops. Most likely they’re the new “national symbols” authorized
by Change 10 to AR 850-5 (25 March 1944).

Vehicles assigned to tactical units anywhere and designated administrative vehicles overseas, still wear the familiar white star. But all other vehicles now sport the following national symbols instead:

ASF vehicles (except contractor operated ones at class IV installations) wear the insignia of the appropriate Service Command;

AAF vehicles flash an insignia prescribed by the Commanding General, AAF;

AGF vehicles carry a symbol specified by the Commanding General, AGF.

What could be symboler?