some i've read (Yaoi of course)

YOU AFFIRM THAT YOU ARE OVER THE AGE OF 18 (OR, IF GREATER THAN 18, THE AGE OF MAJORITY IN YOUR JURISDICTION) AND ARE OF LEGAL AGE IN YOUR JURISDICTION OR RESIDENCE, OR POSSESS LEGAL PARENTAL OR GUARDIAN CONSENT TO ENTER INTO A BINDING CONTRACT. IN ANY CASE, YOU AFFIRM THAT YOU ARE OVER THE AGE OF 13. IF YOU ARE 13 OR UNDER, YOU ARE PROHIBITED FROM USING OUR SERVICE.