For example:

I heard a song by XXXX (as in anonymously no one) and liked it.  Turns out I don't like XXXX's usual style, or for whatever reason, no longer want to be notified of XXXX's tunes popping up here.  Now, is there a way to remove my bookmark after X amount of time?  If not, could there be?

Obviously, not super important.  I was mostly just making sure if I could do this already.  If not, someone could put it on a list of things to do, but I wouldn't be surprised if it doesn't take precedent over other issues But it's a feature I'd like.

Perhaps this post should be moved to Bugs and Requests if this is not already a feature?  Whatever.