I am starting to see this more often then I think we should: Instant Message language and computer geek jargon that frankly the common person will just not get.
Not only that problem, but it is just lazy on the poster's part and cheapens the experts feel we are going for, in my opinion. tl;dr. does not belong in any answer. If you didn't want to read the original posing that is fine and it's fine to make an answer, too, but why start it with jargon that looks like a typing error? Just type out a sentence at the top or bottom, or don't do anything at all. Let the votes and comments tell you if you lost the gamble and made a cruddy answer.
Then we have other oddities like using actual code syntax to say something is or is not the same thing as another thing. Just type out the words. How many more word are there really?
Then further, we are developing our own jargon, unique to this site and more generally the Stack Exchange Network. C.SE to refer to this site, for example. This gets really confusing because you can't even Google search what it means. That kind of jargon is ok in chat, but it likely confuses new users and the casual visitors and might lead to nonsensical responses.
Now I freely admit that I that used some of these before myself, but, hey, I'm only human, and now I've decided to make a conscious effort not to do it.
What does the community think?
Here's what the above might have looked like:
So apparently SNAFU: IM and geek speak / net speak everywhere. That's just terror for noobs.
More than that its just Patrick Swayze, imo. TL;DR is a bit like saying idc about the deets in the OP. It's usually used in a rude way. You didn't want to read, fine. Make a horror show answer anyway, but wo the geek speak.
Then we say code syntax. [item A != item B] != [item A and item B are not the same thing], although I admit the first is shorter plus you get the pow of the "!". Means null to non coders.
Further, our own jargon on C.SE and SE in general. Can't even google that. This will just lead to asdf responses and keep VTC's high.
So I've done this, too. Pebkac error. lol. But, I'm going to stop, sysadmin and mods hold me to it.
This jargon response was just for fun and to make a point that it hardly sounds expert/professional.
When I first noticed "tl;dr" on this site I confess that I did not know what it was. I honestly thought it was a typing error. But I convinced my self that typing errors do not end up on lines by themselves so I googled it.
The convention in most forums for "TL;DR" is to use it as a snide reply on particularly long posts. It's kind of like saying "I didn't feel like reading your post but here is a response anyway." Or more rudely "A post this long from you is not worth reading."
On Christianity.SE the convention seems to always be a synonym for "summary" or "abstract". That is fine I suppose, but then why not just use "summary" or "abstract" or "short answer" and "long answer"? Generally, most of us here are geeky types and find it fun to do odd things like use weird jargon, but I think using "tl;dr" with either convention on this site either inappropriate or unnecessary because other real words exist.
So I still stand by my original post that we should not use this kind of jargon; and for the most part, most users never do.