There are 1: Everyone 2: Registered Members 3: Your Contacts 4: Friends What do "Everyone" and "Your Contacts" mean? Anyone help pls
"Everyone" refers to only registered users, the same as option 2 - I assume it used to be possible for people who weren't registered to see profiles, but now you have to be logged in to do so. "Your contacts" means that only users you've added as friends (by clicking the little "Befriend *name* link on their profile) can see whatever you've set as that level of privacy. Basically, to my knowledge, 1 and 2 effectively mean the same thing, and so do 3 and 4.
I am not sure the 3rd and the 4th options match. At least at another board they didn't. A friend was more than a contact.
It seems that you can be a contact without being a friend, but you can't be a friend without being a contact. It looks like when you add someone to your contacts they're automatically a contact, and if they accept and add you back, you're set as friends. The categories would mostly overlap and you wouldn't often get a contact who isn't a friend, but if you want to be on the safe side, set your privacy as "friends". Also please note that mods and admins can see friends-only content.
