It was about a way to leave an audiobook or podcast to listen to some other music, than later, quote: "come back and pick it up where you left off, without having to memorize the time that you paused."
Now spotify has marked this idea as "implemented".
The thing is they have only implemented it for podcasts but not for audiobooks. Instead they have left the advice, that anyone who would like this feature for audiobooks as well should post a new (!) idea.
So this is why this idea is POSTED again. Hopefully it won't take another 3 years before spotify implements it.