Spectre
Contributor
Padipro:A better place to post a question like this is The Deco Stop. It's much more technical then The Scuba Board.
But... as scuba_steve mentions, it's not a technical question
Tie the bolt snap into one of of the grooves between your hose and your reg. Personally I like to tie mine in the groove made by the hose swivel end. I have heard GUE instructors suggest tying it in the grove between the reg and the hose.
Another reason for the bolt snap is to clip your reg off if you are receiving gas from a buddy... or when walking to and from entry points. Basically any time your reg isn't in your mouth you should consider clipping it off.