hi

'Illegal' (i.e. actually against the law) and 'against the forum rules' aren't quite the same thing, and the forum rules aren't quite the same as the law (any law - remember, there's people here from all over the world!). The forum rules are what apply here (in addition to relevant laws, of course), but they should be pretty straightforward. The quick reference guide to them is here:
worldpf.com/thread/518/quick-reference-guide-forum-rules?page=1&scrollTo=2344

In general when it comes to posting 'humour', you just need to remember that people can only read your words themselves, and not the smile on your face as you post them (or your tone of voice, or body language, or any of the other indicators that people use in 'real life' to judge how words should be understood) - they can't see your intentions, just what you have actually written. Try reading things back to yourself before posting them, with that in mind - I find it helps alot. If it looks like it could be considered 'offensive' that's how other members might see it, and how moderators are likely to have to see it if other members complain, because they can only look at the words that are posted too (they can obviously look at their context, too, but that doesn't always help, and can actually sometimes make things look worse).

I hope that helps - we don't want to lose any members because they didn't realise quite how what they were posting was coming across to others, just as we don't want to have members being offended unnecessarily and unintentionally by things that can be too easily misunderstood.