Here's a few of my favs:
1. If it's clean when you walk in (like the stovetop or counter, for example), it's clean when you walk out.
2. If it doesn't belong to you, don't touch it, or eat it, or drink it, or use it.
3. If it's a reasonable time to be quiet (like 10 PM), be quiet.
4. If you stand up, don't piss on the rim, the floor, the seat, the baseboard, the tub, etc.
5. Flush the toilet.
6. Community property means community replacement.
7. If your room stinks, keep your door closed; if you stink, take a shower.
9. If no-one else in the house salts their language when they speak to you, keep all the f**+s and cocks to yourself.
10. Walk down the stairs at 0430 and 2300--don't run, in boots, while belching and farting.
11. If a bedroom door is closed, knock and wait.
12. You like football and you like to coach the teams from your easychair, in your loudest voice. Everyone else likes to read quietly, or sleep, or study, etc. Watch your game in decibels that do not escape your closed door, or use headphones; coach-at-a-distance in your mind or under your breath, or go to a pub and yell with all the other champs who had the decency to leave the house.