These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Anno Dracula
Genius Bonus: You pretty much need an encyclopedia to catch all the historical references and literary in-jokes.
Crazy Awesome: A book series that features vampire Edgar Poe and vampire Winston Churchill would have to be this. Most noticeable in The Bloody Red Baron, which features vampire flying aces who turn into giant bats with biplane wings.