Friends
I'm happy to add anyone as a friend but I have to put some rules in place:
No VAC or Trade banned profiles - I don't know how you received those bans and I can't trust that you won't cheat or scam again. I might make exceptions for some people.
No Private profiles - These users are likely scammers/bots attempting to send phishing links to people to gain unauthorized access to accounts.
No Suspicious profiles - This could be anywhere from you not having a profile set up, a low friend count, no avatar, or something else I will find.