Armchair Treasure Hunting: What’s the Difference Between Clues, Hints, Red Herrings, and Rabbit Holes?

When picking up an armchair treasure hunt book, sometimes the most difficult task to making a solution is to decide if something is an intended Clue, Subtle Hint, Red Herring, or just a Rabbit Hole. What is the difference between these terms?  And how do we know which is which? …