So, I beat the tank and walk to this area where there's a locked door and three enemies. Some text came on the screen, but unfortunately, this stupid game accidentally clicked past the text before I could read it. Anyway, Big Boss told me to find the enemy uniform to slip past the guards, but I can't find it anywhere. I've been to every single room except for the previously mentioned locked room and one other locked room outside my prison cell. There's no where else to go. I found the armored vest and was hoping that was the uniform, but no, the guards don't react any differently to me. So, where do I get the enemy uniform from?
Never mind. I just tried every single radio frequency and finally that Schneider guy told me it was in the basement. I just started bombing walls in the basement and eventually found it. Jeez, how the hell was I even supposed to know what frequency Schneider was on when no one in the game ever gave me his frequency? And it would have been nearly impossible to find it without him since there was no crack or anything that indicated the wall could be bombed.