Tl;dr

From No LJ Ads Wiki

tl;dr is a typical comment for when something has been drawn out so far and elaborated to the extent that is so exaggerated and huge that it was skipped over because of the sheer size of the document that it would have been way too much to be able to take in and no one's attention span is long enough to read anything like that because it's like an encyclopedia article and nobody wants to read something that reads like an encyclopedia article because those are boring.

In other words: "Too long; did not read".