Are topic featured links just informatibe direct links for users?

Feature link of a topic — does it have any other role than beeing ”just” an informative plus direct link to original source? I mean can I use those via searching somehow, create tags with it or something else?

And my actual headache is how can I put a tag to every topics that are linked to same domain? I wouldn’t need such tag if topics can be found thru searches using feature links as those are shown to users, though.

Am I thinking now too… difficulty?