Like the title suggests, today's puzzle is sponsored by the letters M, G, R and S.

• First two - no pun intended, use the opposite case:
  18SUJ2337307108
• Last three - go postal and give me the forward part:
  18TWR8545674266

Put them after http://www.steamgifts.com/giveaway/ :P

You are alone on this, soldier! Or skip it. No sharing, hinting.. mkay? No. Just no.

Or there will be Charlie Foxtrot:

MEMOIR WILL KILL YOU IF YOU SPOIL THE PUZZLE.

Should end Oct 2nd, 2000 ZULU.

Update: (at least) 21 solvers and 16 entries

Also maybe some hint about first two, if you can't seem to narrow it down try to actually take a broader perspective.

Solution

One hapless prospective solver even asked if letters M, G, R and S are just random title or do they mean something. Well of course they mean something! I can't believe some people were missing this. That was the key to solving this puzzle. The title was using NATO phonetic alphabet just for a flavor though, to keep the military theme and not to be too obvious for a title, but I didn't want that part to be in the puzzle itself so the first line of the description spells it pretty clearly. Or so I thought.

I probably should've used lower resolution / bigger quadrants as after getting what MGRS is, people tended to focus on the trees instead of on the forest and I meant the general area not the spefic place at the address generally pointed by the coordinates. Too much faith in Google maps, people!

Anyway I just took coords of DC and Sainte-Sophie from wiki and translated them to MGRS without thinking what is around these coordinates EXACTLY AS GOOGLE MAPS SHOWS. But since people had trouble with the first one, focusing too much on the White House and area, I gave a hint of taking wider perspective (and I meant that pretty literally).

So yeah actually the capital of the Unitated States is Washington, District of Columbia = D.C., often actually pronounced just DC for short (this was bit of an American bias as I think it may not be obvious to non-Americans that DC = Washington, DC for short). That's the first two. My "pun" reference was about "capital" of the Unitated States vs capital letters.. to use lowercase.. Eh. And the second part was forward sortation area from postal code of Sainte-Sophie in Quebec, Canada.

Oh, and MGRS = Military Grid Reference System if you searched for letters M, G, R, S together even with spaces this should be pretty apparent, especially if you account for the military theme. The strings I gave are coordinates in MGRS. Just use some conversion to more common format (like longitude and latitude) and use that to localize what they are pointing to.