I started this on Seel'vor's "seelvorfanfiction" Yahoo! Group. Credit for #43-45 goes to the inimitable Lord of Bones. I may also intersperse short vignettes extrapolating on some of the rules as separate chapters.
Things Gryffindor House Are No Longer Allowed to Do
1. Testing the theory that cats always land on their feet by tossing Mrs. Norris off of the Astronomy Tower is not permissible.
2. Professor McGonagall's Animagus form is NOT excluded from the above rule.
3. Asking Argus Filch whether he considers himself to be "Mr. Norris" is not acceptable.
4. Even if he answers in the affirmative.
5. Especially if he answers in the affirmative.
6. Ms. Mun, threatening to make Cerberus bosin-tang will not endear Groundskeeper Hagrid to you.
7. Messers Weasley, quills are not to be used in that fashion. Ever.
8. Parchment is not an acceptable substitute for bog-rolls.
9. Especially not if you return them post-use to where you found them.
10. Even if it is Professor Snape's room.
11. Especially if it is Professor Snape's room. How did you break into his private quarters, anyway?
12. Mr. Potter, there is no such thing as 'The End of Line Clause', and it certainly does not entitle you to form your own harem.
13. Mr. Potter, put those girls back!
14. No, Mr. Weasley, you do not get a harem, either.
15. Miss Granger?
16. Under no circumstances are student harems allowed in within Hogwarts!
17. Miss Tonks, while I admit that you are no longer a student here, you are not allowed to be part of a Harem on Hogwarts property!
18. Nor are you allowed to be part of a harem with Hogwarts students, regardless of whether you are on school property or not.
19. Mr. Longbottom, you are not permitted to tell Miss Lovegood that 'snorkack' is a Ukranian euphemism for oral-anal intercourse.
20. Mr. Potter, you are not permitted to 'demonstrate' the above!
21. Not even if Miss Lovegood says 'pretty please'!
22. Mr. Jordan, under no circumstances are you to swing Mrs. Norris overhead by the tail.
23. The "Spin the Kitty" song is no longer allowed to be sung near Caretaker Filch.
24. Caretaker Filch's name is spelled with an 'i', not an 'e'.
25. Mr. Longbottom, it is not permitted to substitute anything for Professor Flitwick's tobacco.
26. Messers Weasley, you are not permitted to tell the First Years that the appropriate method of greeting a member of Slytherin House is, and I quote, 'A boot to da head'!
27. To whomever poured the purgative potion onto Headmaster Dumbledore's Lemon Drops, you have just cost Gryffindor House one hundred House Points. Oh, and the Headmaster sends his warmest thanks.
28. Mr. Finnegan, regardless of how much you personally admire Alastor Moody, hip flasks are not an acceptable addition to the Dress Code.
29. That had better be pumpkin juice in there, young man...!
30. Miss Granger, while your writing was thought-provoking, poignant, and clearly well-researched, I would like to point out that your subject of "1001 Reasons Why Draco Malfoy is a Mouth-Breathing, Inbred, Coprophagiac Pouf" is not in accordance with Term Paper guidelines.