The only time its ever been made clear to me as I feel it should be is the "I have a boyfriend".
Most Helpful Girl
Personally I tell a guy when I am not interested.
But for the other scenarios, I kind of friendzone him when I am not sure. I can't tell right away if I want to be in a relationship with him, neither can I tell if the one I am interested in will be interested in me so I keep the guy around because who knows! Or the guy is in the friendzone because I like him but he isn't making it clear if he likes me too so I put him there until it is clearer.
Friendzone is a zone, for me, that the guy can come out of easily.
Maybe it's kind of mean but that's the way it works in my head.
Most Helpful Guy
Look, generally people you talk to aren't monsters and have no desire to hurt other people. They are just trying to avoid hurting your feelings and avoiding having to face an awkward confrontation. It also leaves a future possibility open with you should events come back around to you again one day.