This principle is also known as Chekhov's Gun, named after Anton Chekhov, the author of many famous plays in the late 1800s. The underlying literary principle is when an element is presented, by the third act, it should be used.
You can see this throughout the play, novel, short story and movie world. Most avid moviegoers who pay attention can spot the Chekhov's Gun item in the first hour that will come back around. Some authors use this in scenes, especially fight scenes. In Patriot Games, for example, we get the foreshadowing of how Sean Bean is about to be killed when, for no apparent reason, Harrison Ford picks up something and the camera lingers on the anchor stuck in the boat. Actually, I hate when they foreshadow so closely to the event, as I prefer it is something we can see towards the beginning that becomes important later. In The Others, we get to see some weird creepy old white-eyed lady, and we assume she's an evil spirit. In the last act, we find it's something we didn't expect. Sorry if the original spoiled the ending, if you hadn't seen the movie.
The bottom line is when you introduce something, make sure it is used (even as a red herring), or you're wasting everyone's time by putting in material that does nothing for the story.