With some of these weapons/items they will crash the system when playing as Snake. These were thought to have been able to be used after beating Olga, but this has been proven false.
If you have Snake codes for the following weapons: SOCOM, PSG1, RGB6, NIKITA, Stinger, Claymores, C4, AKS-74u, M4 & PSG1-T
And the following items: D Microphone, Book, Field Uniform & NVG
DO NOT USE THEM, THEY WILL CRASH THE GAME.
(NO permanent damage is done.)