Hmm, personally, I'd let 11+ in. Although it would probably lessen the forum's quality of people, 11 and 12 is really the age that you have the most unanswered questions about puberty. Every-freaking-little thing about puberty was confusing to me when I was late 11 early 12
.. I was so innocent, I didn't even realize I was masturbating until I was almost 13.