People used to (still do?) post +rep or -rep if they like or dislike you or something you've done. "rep" is short for "reputation." A long time ago, there was a site that would trawl steam profiles and collect +rep or -rep statements and score a profile based on how many of each it found, but I'm pretty sure that site's defunct now.

what does rep meaning

+rep mature guy and good at making guides

Just a heads up - if you were on my friends list, and now you're not, I did some winter cleaning. Phishers, spammers, people I almost never talk to, people I find annoying, or people who added me and never even talked to me to explain why were deleted.

Wanna stay on my friends list? Simple - talk to me occasionally (like, at least once every three to six months or so) and don't piss me off or make me regret accepting your invite.

Not shown - inside the second medkit is a tiny Medic.

What's inside a medkit, you ask? http://imgur.com/a/8UHTp