Strange how Snake doesn't normally wear a belt
That is, in the bank robbery opening, Snake doesn't have one, so that's his "default" look. Not only that, his bdus/combat pants don't even have belt loops on them. That seems kind of weird as it looks like they don't have those little straps on the side that allow you to adjust the waist either, in absence of a belt to hold the pants up. Most army surplus pants I've seen have belt loops on them at least. (From what I've read on boards like the RPF I'm not the only one who picked up on this, it seems the bdu pants were custom made rather than off the peg, apparently even the camouflage design fabric was custom, presumably to make Snake look even more unique.)
Understandable that before the mission they issue him with a utility belt with weapons, etc, so it would have been odd if he was wearing two belts, but all the equipment they gave him could easily have been just clip-on pouches (note the holsters and pouches on the table), then when he was captured by Duke and his gang he could have kept his belt and just had his equipment taken away.
Strange nitpick, I know, but I just thought it was a funny thing about his costume. It looks strange belt-less. It seems most artists (both fan artists and comic artists) think so as well, as they add one, I noticed this in the recent comic series. The only artist who seems to have got it right is whoever is drawing the new BTILC/EFNY crossover comic, he has Snake's belt hanging at an angle over the top of his combat pants, almost in a "gunslinger" fashion. Given JC's love of Westerns, I wonder if that was the original idea. (Weird the little things you notice when you've watched the movie countless times.)