:L <- the hell is that? you post it like, every time. It vaguely looks like an emoticon such as: :I or :T it just kinda looks like a drooling face...
I actually have no idea, my friends and I always took it to be a laughing face, maybe the L stands for laughing, I don't know, but it's my go-to smiley face, so i'm afraid you may have to put up with it for a little longer :L.