"Too long? Don't read"; "Don't bother reading if it doesn't interest you".
Not to be confused with tl;dr.
When you previously gave some information or made a joke and want to give more clarifying info, but also want to admit that knowing said info doesn't gain you much benefit either.
Nobody wants their app to crash. Yet they added `Abort()` in the new version!?
tl?dr
Well, they actually added it for ... reason x and y ... *much text*
Used when some geek delves too far into a technical explanation. to some girl on MSN or AIM.
Geek: "Hey my webcam isn't working, sorry. I could explain why but won't"
Girl: "Okay"
Geek: "Lol, I took it appart to make it into an infrared cam. It's pretty easy you just cut a bit of film negative up and put it inside, taking the old filter out. Means it see's infrared light instead of visible, cause the film negs blank that out. It's pretty cool I'm wearing a black shirt and it shows up white on the camera."
Girl: "tl;dr"