What Zarago said.
There's no way to validate that your parents have given consent, but they'd like everyone under 18 to get permission to. It's just that some parents started throwing a fit because of some of the rp content and... erm... buttswing-related incidents as of late. Pfft, parents what are you doing.
But in all actuality, you and/or your little siblings shouldn't be on the internet if you're under the age of thirteen; I'm not being an age-ist or age discriminatory - that's actually kind of a law. Granted, it's a wonky US law, but still.