First of all, I am not professing to be an expert, I have an interest in vehicle markings and I am just sharing what I have gathered.
The information I give is based on notes and memory from when I was active in the Marines from the late ‘70s to the late ‘80s, and looking at as many photos (and that’s a lot!) and actual vehicles as I can since then. Try as I might, I can find no TMs or other “official” marking source for Marine vehicles. This may be a problem for active Marines as well, as the markings are sometimes inconsistently applied.
Note- I am not refuting anything anyone else has said, this is purely what I saw or have found.
So, with the late ‘70s to the present in mind-
There are basically two types of Marine vehicles, tactical and non-tactical. The tactical vehicles are primarily for use in the field, non-tactical are used everywhere else.
Non-tactical vehicles tend to be painted overall Marine green with yellow or black markings on the door. The Dodge vans I used to drive around were overall glossy green and had on both front doors and the left back door in yellow stick-on letters:
U.S. Marines
(6 numbers)
For official use only
I remember two-wheel drive Dodge pickups, overall green with similar markings on the doors, but not on the back, sometimes in yellow sometimes black (that has a nice rhyme to it…) and often without the “Official use..” bit.
We had lots of M880s series 4x4s, M151A2s, and some M715/725s; they were almost all painted Merdec camo (like Bob H and N1265 avatars) and had:
USMC (6 numbers)
painted in black (on the front fenders of the 880s, side of the hood of the M715/M151). I never saw yellow markings on camo trucks. I don’t remember there being M numbers on these vehicles, but there may have been.
Around 1982, I helped re-mark some M60 tanks that had been received second hand from the Army, they were painted Merdec and had the above markings stenciled onto the sides.
In the early to mid 80s we got Humvees and the Chevrolet CUCVs to replace all the above vehicles, they arrived in the 383 green/brown/black camo and everything else began to change to that scheme. Vehicles in that scheme pretty much all had the M number on the side and/or back, everything from trailers to trucks of all sizes, to LAVs and whatever. The markings are the same on most 686 tan vehicles.
The side view of the M813 is from the mid-90s, the rear of the bed is from last year. I just used those because I have a LOT of M813 pics and they illustrated what I was trying to say. My truck was last painted by the Marines in 1993 and the markings follow the same pattern.
I’ll shut up now……