I don't know who originally wrote all of this (probably a collaborative effort), but I found it here:
I don't think I have space enough to post the whole document, but here are a few select favorites of mine:
1. Cannot base characters off the Who's drummer Keith Moon.
24. Even if the rules allow it, I am not allowed to summon 50,000 Blue Whales.
28. The Goddess' of Marriage chosen weapon is not the whip.
73. Not allowed to name my cudgel Ceremonial Whoopass Stick.
178. There are no profanities in Celestial.
214. There is no prestige class Drizzt Slayer.
219. In formal introductions to royalty, I must not introduce my companions as just "The Other Guys".
224. I cannot insinuate elf chicks are all easy, even though you never hear about a half gnome do you?
243. Cannot cast haste on the king during a long winded speech to get him to hurry the hell up.
260. Gnomes do not have a racial bonus in bobsled.
272. No skill allows specializing in defenestration.
299. I do not get any XP for anyone I kill by stampeding sheep.
301. "Well Hung" is not a physical, social or mental trait.
330. The Halfling Paladin does not represent the Lollipop Guild.
374. I am not to combine the advantage Fearless and the disadvantage Curious in the same character again.
378. I can cannot give my character the moniker "Tim the Barbarian". Especially since he's the bard.
384. The titles "Viking" and "Obstretrician" are mutually exclusive.
409. I will not cast darkness at the magic missile.
412. I will not try to skip to the main boss dressed like a singing telegram.
419. Spankings generally will not change evil alignments.
461. Tasha's Uncontrollably Hideous Sister is not a real spell.
467. There is no 'accidentally' slipping a Smite Evil into a pillow fight.
481. I am forbidden from doing anything that ends with a snarf, rimshot or spit take.
484. If the word 'Mullet' appears anywhere on my samurai's character sheet, he's vetoed.
486. No how tough the encounter was, I will keep the congratulatory ass slapping to a minimum.
487. Halfing mating rituals do not include beer can crushing, power belching, or Lynyrd Skynyrd trivia.
502. If my name isn't Grimlock, can't start every sentence with "Me Grimlock"
510. After a bloody battle, I will not celebrate by lying down and making carnage angels.
544. I will not cast Gate to bind an infernal creature of power to my bidding and make him mow the lawn.
588. Paladins are immune to STDs, but if I take advantage of this ability, I lose it. Wonderful paradox, isn't it?
593. Tensor's Herniated Disc is not a real spell.
Okay, that's enough of that for now. Go read the rest if you want, but I'm out.