Steel Soldiers now has a few new forums, read more about it at: New Munitions Forums!
Microsoft MSN, Live, Hotmail, Outlook email users may not be receiving emails. We are working to resolve this issue. Please add support@steelsoldiers.com to your trusted contacts.
In the Marine Corps anyone who deals with radios, communications, wire etc (25xx or 28xx) MOS's are usually housed in "Comm Companies or Comm Squadrons/Bn's or Radio Bn".
The link is the branch insignia for US Army Signal Corps. The Marine Corps doesn't wear "branch" insignia to denote specialty, were all Marines.
Could be just a "Flammable" warning if that's one of the fuel tanks. A higher resolution would help for sure. Standard "tac marks" would be vehicle Serial Number, USMC, Tire Pressure, Center of Balance, Landing serial number, GVWt etc.
They almost look like Marine Corps Eagle, Globe and Anchor emblems within a circle. Not uncommon as units would frequently paint them even though technically unauthorized.
Check out Rich Johnson's M37 shelter pictures on his site, just search his name and include the M37 and it should show up. He has quite the collection of shelters mounted in M37's and several are USMC units, you might see the insignia you are looking for..