How do you tag someone from outside or inside a post ? I can't find the menu option ? Thanks
Just put an @ sign in your post and the username of the user immediately afterwards.
There is a gotcha though, as in some cases their display name may not be the same as their username, so if it doesn't highlight their name in blue once you've posted, then check their profile page for their username (e.g. to pick one at random, IFISACava's actual username is cavalier)