I notice in the sub-forum rules, there's always a currency cap listed (in volts). What does it mean?

I might have missed it or went brain dead as I stared the explanation in the eye.

Thanks.

@Q t e a p o n: No memes? Thank the rules!
I think that's my question answered, thank you. Though I might dare to suggest that this info be available somewhere that makes sense, if it's not already (I mean it's available here, if that's the most sensical place).