I Thought It Meant/X-Z

Just to clarify:

X

Xanatos Funeral is not about the death of that character (he's likely faked his death anyway).
Xanatos Gambit is not about the real name of one of the X-Men.
Xanatos Gilligan is not missing a slash in there (mercifully).
- It's not about an elaborate plot to trap a group of people on an island permanently either.
Xanatos Roulette is not a casino owned by that character in Gargoyles.
"X" Makes Anything Cool is about the letter X. It is nothing like Everything's Better with Indexes. It also isn't a subtrope of Watch It Stoned.
X Meets Y is not a more flexible version of Boy Meets Girl.
- Nor is it Shipping applied to the alphabet.
- It's not an origin story about fertilization of an egg, either.
- It is also not a crossover between X-Men and Y: The Last Man.
X-Pac Heat is not what is given off when you burn Sean Waltman to a crisp, though it does describe the feeling of wanting to burn Sean Waltman to a crisp.
- It also has nothing to do with Pac-Man porn.
- Neither is it about disliking an Expansion Pack.
The Xylophone Gag is an old cartoon gag, but it's not the one where a character rams into a piano or xylophone head-first, and, upon looking up, has the instrument's keys sticking out of their mouth as a sort of prop-induced Wild Take of pain.

Y

Yandere is not about a dere girl named Yan.
Yangire does not mean that Ya ng will become more dislikeable when he's angry.
Yeah! Shot is not a reply to Why Don't You Just Shoot Him?.
- It is not being shot after a successful escape attempt.
- It's not an appropriate response to a Quip to Black.
Ye Olde Butcherede Englishe is not nearly as relevant to Sweeney Todd as you might think.
A Yin-Yang Bomb is not what the Chinese use to fight Mighty Whiteys, Scary Black Men and... Oh dear, Unfortunate Implications anyone?
YKTTW is not a rival site to YTMND.com. You might be looking for PTKFGS instead.
Yoko Oh No is not the sound you make when Yoko from Tengen Toppa Gurren Lagann kisses someone, and the recipient dies a very, very manly death at episode's climax.
- Or the reaction when Graham Jones stabs her.
You Bastard is not one of the Insult Tropes.
- It's also not about whoever killed Kenny.
You Can't Fight Fate is regularly disproved on Magical Girl Lyrical Nanoha, but not because people go around successfully picking fights with the Dark Magical Girl. Incidentally, these Fate puns are way too easy to make.
- If you're Negi Springfield on the other hand... good luck.
You Can't Make an Omelette is not a criticism on someone's cooking skills.
You Can't Thwart Stage One is not a criticism of a player's skill at Nintendo Hard games, nor is it a case of a game's first stage being Unwinnable.
You! is not an Unusual Euphemism.
You Fail the IQ Test is not about taking an IQ test, and getting an F, although if a character did that, it would certainly be an example.
You Got Spunk, thankfully, has nothing to do with Rule 34 applied to Item Get.
You Gotta Have Blue Hair does not deal with obligatory Blue Hair Days.
You Have to Burn the Web is not about setting fire to the internet (even though we wish it was).
You Know What They Say About X... is not about rumors on the third-to-last letter of the alphabet, rumors about a certain Maverick Hunter nor the EgoSoft space flight simulator series.
You Lose At Zero Trust is not a double negative about excessive naivete.
Yo Momma is not related to a musician.
You Put the X In XY is unrelated to female genetic material.
You Should Know This Already is actually full of spoilers.
- It's also not a Stock Phrase a frustrated Mr. Exposition yells at the rest of the cast when he's tired of pointing out things that should be common knowledge.
You Shouldn't Know This Already is not a redirect to "Early Arrival Spoiler".
Your Days Are Numbered is not about calendars.
Your Secrets Safe With Me Superman is not what Lois Lane said to Superman when he told her that he was an alien from outer space.
Your Size May Vary has nothing to do with any sort of "male enlargement."
Your Vampires Suck does not nescesarily have to do with the way that they feed.
Young Gun is about young people using guns to protect themselves, Young Guns is the name of a movie.
Yo-Yo Plot Point is not about the author stopping to greet the viewer to remind him/her about plot points.
Yuri Fanboy is not in any way related to the villain from Command & Conquer: Red Alert 2, the hero from Shadow Hearts, the guy who spends half of Planetes looking for a compass, the voice actor that plays Sasuke and Suzaku in English, the male lead of Final Fantasy Crystal Chronicles: Ring of Fates, or the titular doctor in Doctor Zhivago. Or at the very least, we hope it isn't... It does, however, occasionally describe some fans of The Dirty Pair. Or even the lead character of Tales of Vesperia.
- Or somebody who's a fan of Yuri Gagarin, the first person in space, though he does have a lot of fans.

Z

Zeppelins from Another World has absolutely nothing to do with Led Zeppelin.
A Zerg Rush has nothing to do with the tactics of the woman who broke Ken Jennings' win streak on Jeopardy!.
Zero-G Spot is not a woman lacking one. Nor is it proof that a particular Mega Man X character is actually a girl.
The Zeroth Law is not "protecting humanity as a whole trumps obeying the Three Laws of Robotics". Conversely, a Zeroth Law Rebellion does not involve going back in time and writing something that becomes the Trope Codifier for a trope Shakespeare currently codified.