Forum rules tl;dr: Don't act like a 12 year old, don't be a dick, don't spam, keep it sfw, no alt accounts, no large sigs, use coloured text sparingly, no illegal shit, and your behaviour on here is subject to staff discretion.
The last part is important, because the rules can't cover every aspect of human behaviour. You are expected to exercise your own judgement in what is right or wrong. The warning system is meant to give you the opportunity to stop doing something that would get you in trouble.