How can I eliminate irrelevant (and obsolete) answers?

Question

As Ubuntu grows older, I'm finding that some answers no longer apply to the version that I'm using -- and if I don't know the answer I wouldn't know that the answer that I read is not applicable to my situation (unless this is stated somewhere in the answer).

Let me give two examples:

1. I am using 15.04 on one of my computers. This version has adopted "systemd" (vs upstart). Consequently, there will be a large number of answers on AskUbuntu, that will tell me how to install an app using upstart -- in my situation I would consider these obsolete answers.
2. A second example has to do with the use of the command "gksu". Just recently, I read an answer stating that the use of gksu is not recommended (by Ubuntu developers). See: Why is gksu no longer installed by default? If this is true, then questions regarding the use of gksu are irrelevant (and should be considered obsolete), and the amount of time I spent reading answers about gksu was all for nothing. And, had I not read this one answer I would have continued to use this command.

So, should there be some way to bring to my (and other 15.04 users) attention, that these answers are not relevant to my use of 15.04? Or, is there some way to do this already?

Answer 1

You'll see on many posts that are applicable across releases that answers have headers that say, for example:

For 13.04 and later

Until 12.04

And so on. If you're sure that the post is no longer applicable from a release onwards, add a header stating so (and, hopefully, an answer that's applicable to that release).