Keep it civil, do not flame or bait other users. If you notice anything illegal or inappropriate being discussed, contact an administrator or moderator.
There's certainly much weirder that's fairly common like size difference or oviposition but the above are the common threads that are very likely to be included to some degree. And a few preferences like smaller/mid sized breasts that brings in loli/flat/trap but I wouldn't say they're in the fetish list