1. Thou shalt not use dicks as thy profile picture
2. Thou shalt not proposition sex or sexual acts, including fantasy fulfillment, upon initial contact.
3. Thou shalt not send gratuitous sexual tripe without seeing if the recipient is into said erotic fantasy.
4. Thou shalt not covet a married/taken/otherwise spoken for sub/slave.
5. Thou shalt not proposition a submissive to Dominate you.
6. Thou shalt not request nude shots of random strangers.
7. Thou shalt not talk as if you are a teenager texting her BFF4lyf.
8. Thou shalt use spell check.
9. Thou shalt not abuse the ellipses.
10. Thou shalt accept rejection sans butt-hurt and not bother them again.
ADDENDUM: Bonus 11. Thou shalt read a profile in full to the end before sending a private message or a friend request.
– Collected from various versions