These cracked me up. The list is a bit long, but it’s worth it! Enjoy!
1. No matter how good a fake Australian accent I can do, I will not imitate Steve Irwin during Care of Magical Creatures class.
2. “I’ve heard every possible joke about Oliver Wood’s name” is not a challenge.
5. I will not go to class skyclad.
6. The Giant Squid is not an appropriate date to the Yule Ball.
7. I will not use Umbridge’s quill to write, “I told you I was hardcore.”
10. If a classmate falls asleep, I will not take advantage of that fact and draw a Dark Mark on their arm.
12. Starting a betting pool on the fate of this year’s Defense Against Dark Arts teacher is tasteless and tacky, not a clever moneymaking concept.
13. Seamus Finnegan is not “after me Lucky Charms”.
15. I will not tye-dye all of the owls.
16. I will not reenact Harry Potter Puppet Pals in the Great Hall
17. Or anywhere else for that matter.
18. I will not shave Mrs. Norris.
20. I will not write all my essays in red ink claiming it is blood.
21. I will not ask Lupin if it his time of the month.
22. I will not provide Luna Lovegood with Coast to Coast AM transcripts.
23. I will not bring a Magic Eight Ball to Divination class.
24. I am not allowed to tell Hufflepuffs there is no Santa Clause.
26. I am not a sloth Animagus.
27. I am not allowed to steal Professor Flitwick’s wand, hold it over my head and laugh as he tries to reach it.
28. I am not allowed to have a reticulated python, snow leopard, Tasmanian devil, or piranha.
29. I do not weight the same as a duck.
30. Remus Lupin does not want a flea collar.
32. I will not kiss Trevor.
33. I will stop asking the Arithmancy teacher what the square root of -1 is.
34. Skiving Snackboxes are not a suitable gift for first-years.
35. Any resemblance between Dementors and Nazgul is coincidental.
36. I am not allowed to sneak into Professor Snapes private chambers to watch him sing “I Will Survive” in the mirror.
38. I am not allowed to draw a smiley face on my arm and tell everyone it’s the new Dark Mark.
39. Asking “How do you keep a Gryffindor in suspense?” and walking away is only funny the first time.
40. I will not offer to pose nude for Colin Creevey.
41. I will not insist that the trees in the Forbidden Forest are Ent wives.
42. It is a bad idea to tell Professor Snape he takes himself too seriously.
43. It is a bad idea to tell Professor McGonagall she takes herself too seriously.
46. I will stop asking when we will learn to make “Love Potion Number Nine.”
49. If Ginny Weasley wanted to borrow my Darkover books, she would have said so already.
50. I will not take out a life insurance policy on Harry Potter.
51. Sirius Black did not found the Sirius Cybernetics Corporation.
54. I will refrain from wearing black leather gloves at all times and saying “Hogwarts is mother, Hogwarts is father”.
58. Hogwarts does not have a student council. Even if it did, they would not wear the rose seal. Therefore, I will cease going after the prefects with a sword.
60. I will not refer to Umbridge as Queen of the Toads, even if she really is.
63. I will not refer to Aragog as “Charlotte.”
64. Professor Flitwick’s first name in not Yoda.
68. I will not “borrow” a prefects’ badge for Peeves.
69. I am not the Defense Against the Boring Classes Professor.
70. Nor am I the Care of Witches’ Underwear Professor.
71. I am not a professor at all.
73. I will not replace Professor Snape’s pumpkin juice with Skele-Gro.
74. It was not an honest mistake.
76. I am no longer allowed in the student laundry.
77. Or the teacher laundry.
78. Nor am I ever allowed to cast an Invisibility charm again.
79. While wand safety is an important issue, I am no longer allowed to distribute any pamphlet which makes reference to Belinda the Buttless.
80. It is generally accepted that Cats and Dragons cannot interbreed and I should not attempt to disprove this theory, no matter how wicked the result would be.
83. Gryffindor courage does not come in bottles labeled “firewhiskey.”
84. Charming the label does not change anything.
85. I am not allowed to eat Chocolate Frogs in Potions class.
86. Even if I brought enough for everyone.
87. Emptying a bag full of them onto Professor Snape’s desk to prove this is unacceptable behavior.
89. No matter what Professor Umbridge may tell me to the contrary, I am not authorized to form press gangs.
90. Chemistry and Potions don’t mix.
91. Testing the above is not funny.
92. Crucifixes do not ward off Slytherins, and I should not test that.
95. The proper way to report to Professor McGonagall is “You wanted to see me, Professor?” Not “I have it on good authority that you have no evidence.”
96. I may not insinuate that all beautiful American exchange students to Gryffindor or Slytherin House in Harry Potter’s Year are Lockhart’s misbegotten heirs, even if it’s true.
97. I am not possesed by the ghost of Lady MacBeth.
98. Neither is The Fat Lady.
99. When someone accuses me of not wearing any drawers, I should ignore them. Attempting to prove them wrong is indecent.
100. Especially if I can’t.
102. Using the Engorgio charm on certain parts of the human anatomy is not permitted on the school grounds, not even for entertainment purposes.
103. Professor Snape does not enjoy being called “Snookums”.
104. Neither does he respond favorably to “Sev”, “Snapey-Poo” or “Debbie”.
105. First years are not to be fed to Fluffy.
107. I am not authorised to sell incriminating pictures of the faculty to students.
108. Giving the same pictures out free of charge is also frowned upon.
109. Dumbledore is not Santa; he does not wish for me to sit on his knee and demand presents, especially not in June.
111. A wand is for magic only; it is not for picking noses, playing snooker, or drumming on desks, no matter how bored I am.
112. It is inappropriate to slip sample bottles of Selsun Blue into Professor Snape’s personal postbox.
113. I will stop referring to Hufflepuffs as “cannon fodder.”
114. I will not impersonate the Swedish Chef in Potions class.
116. My headmaster’s name is Albus Dumbledore, not “Gandalf.”
117. Neville is not my valet.
118. When given a directive by my house prefect, I should not insist that “we don’t need no stinking badges.”
119. First-years should not be encouraged to befriend the Whomping Willow.
122. Novelty or holiday-themed ties are not to be worn with my school uniform.
123. There is no “open-mic night” at Hogwarts.
124. I will not use my socks to make hand puppets of the Slytherin house mascot.
125. There is no “bring a muggle to school” day.
126.And I should stop insisting there is.
127. I should not ask Professor McGonagall if, while in cat form, she has ever coughed up a hairball.
129. The fact that Draco Malfoy is short, blond, pale-eyed and rat-faced is no reason for me to tell the Slytherins that Peter Pettigrew should be paying Narcissa child support.
131. When fighting Death Eaters in the annual June battle of Good vs. Evil, I will not lift my wand skyward and shout, “There can be only ONE!”
132. I will not refer to any Death Eaters as “Trixie.”
133. Even if it is a legitimate nickname.
134. I will not tell the Muggleborn first-years that the Forbidden Forest’s real name is Mirkwood.
136. I am not to conjure the words “DRINK ME” onto the vial of any potion in Snape’s classroom.
139. The next time that I see Rita Skeeter, I am not to threaten her with a can of Raid.
140. Should I see a Death Eater wearing a white mask, I should not start singing anything from “Phantom of the Opera.”
141. I should not refer to DADA professors as “canaries in the coal mine.”
143. I will not put books of muggle fairy tales in the history section of the library.
144. I will not send pictures of magical creatures to the Weekly World News.
145. I will not cover myself in ectoplasm and walk out of a fireplace, saying I took the “Flu Network”.
146. I will not refer to “The Grim” as a nice doggy.
147. I will not refer to Professor Lupin as a nice doggy.
149. I will not subvert the lock on the fourth-floor girls’ bathroom and sell its location to first-years as “The Chamber of Secrets.”
151. There is not now, nor has there ever been, a fifth House at Hogwarts. I am not a member of that house, nor am I its founder.
152. When applying for a post at the Ministry of Magic after graduation, I should not cite “Fred and George Weasley” as my greatest influence at Hogwarts.
153. “Putting down Lord Voldemort” is probably not smart, either.
154. I am not allowed to ink my owl’s feet, have it walk across a parchment, and sell the result as cheat sheets for Ancient Runes, even though Crabbe and Goyle keep falling for it.
155. I will not refer to the Accio charm as “The Force”.
157. I will not enchant the telescopes on the Astronomy Tower to display non-existent constellations during O.W.L. exams.
158. Albus Dumbledore’s proper title is “Headmaster”, not “My Liege”.
159. A Muggle “vacuum cleaner” is not acceptable Quidditch equipment, even if it has been enchanted to fly.
161. Sending rings to the nine senior faculty at Yuletide, with the return address “Voldemort,” is not funny.
162. Professor McGonagall does not have an inappropriate relationship with Mrs. Norris.
163. I will not create a pin-up calendar of the Slytherin girls and call it “Voldie’s Angels”.
164. Professor Flitwick has heard all the “swish and flick” jokes before, and is very, very tired of them.
165. I will not send Professor Snape toothpaste and shampoo for Christmas.
166. I will not tell Professor Trelawney that I prophesied her death.
168. I will not refer to Professor McGonagall as Catwoman, no matter how funny she would look in tight leather.
169. Nor will I ask her if she is Catwoman in disguise.
171. I will not use Slytherin and Gryffindor first years as Christmas decorations.
172. I will not dye the Death Eaters robes pink.
174. Insisting that the school acquire computers and network the buildings is a pointless request.
175. Calling the Ghostbusters is a cruel joke to play on the resident ghosts and poltergeists.
177. If asked in class what the Avada Kedavra curse does, yelling “It does DEATH!” may be correct, but is not the manner in which one should answer.
178. I am not allowed out of my dorm when visitors from the Ministry are here.
180. I will never again use the spell used to enchant bludgers on peas.
181. Or tomatoes, plums, oranges, or any other food item. Or any other item that is not a Bludger.
182. I may not have a private army.
183. Not even if it technically belongs to someone else.
184. I should not encourage the house-elves to unionize.
185. I must stop referring to the professors by the embarrassing nicknames they acquired in their school days.
188. “Y’all check this shit out!” is not an appropriate way to announce that you are about to perform an experimental spell.
189. Portable Swamps are not funny.
191. Bubotubers are not filled with tasty honey, and I must not tell First Years that they are.
193. Mad-Eye Moody knows his eye is creepy, he does not need to be told… again.
194. Stealing first-years’ clothing and then tossing it into and around the whomping willow is highly frowned upon.
195. Mrs. Norris does not like playing with blast-ended skrewts.
196. Sneaking slugs into Ron’s food is not funny. He does not like being reminded of his “incident.”
197. Trying to out-argue a Slytherin will lead to no good.
198. Despite popular belief, Hufflepuffs are not soft and squishy. Do not treat them as such.
199. I am not the Wicked Witch of the West.
200. I will not refer to Professor Umbridge as such either.
201. I will not melt if water is poured over me.
202. Neither will Professor Umbridge.