Don't overlook the possibilities of badly written policies. Ideally, if they're comprehensible at all, they should ban what you need to do, while having loopholes that mean you can do what they're trying to forbid.

For example, an alcohol-and-drugs policy that (a) bans illegal drugs, but only if they impair your performance; (b) accidentally bans the use of alcohol-based cleansers; and (c) accidentally bans salespeople from paying for a meal with a customer if the customer orders alcohol.