Twenty-Five Rules For FanFiction.

The sole purpose of this is to set what I believe is the proper way a fanfiction should be written. This is just my opinion, so I don't expect you to agree with everything I have on this list.

Fanfiction slang you need to know before reading:

OOC: Out Of Character
OC: Original Character
AU: Alternate Universe
PM: Private Message
beta: short for betareader. Is a reader/author that checks another author's story for spelling and grammatical errors in a story. The author of a story usually sends a chapter or story to their beta for them to complete this task.
review: what a reader should do if they like an author's story. Note - authors like long reviews best.
yaoi: Male x Male love
yuri: Female x Female love

Twenty-Five Rules for FanFiction.

1. Do not write fiction about real people. I don't care if you're a "fan" of them. They have their own lives, and they don't need you screwing with them.
2. OCs - don't make an OC a main character. No one cares that "Charlotte" is so pretty and talented and perfect for Harry Potter. You can have them, but make sure the story centers around the characters everyone knows.
3. Furthermore, don't make an OC after yourself. It's dumb, and dare I say it's desperate. Especially if that OC is paired with one of the actual characters. That's basically saying you make out with your stuffed animals.
4. Don't bash pairings. Seriously, it's immature. If you do bash even the slightest, make sure to note it in the summary. Some people are very picky like that.
5. Flaming - it does nothing but turn people off. If you don't like what you see from the summary, don't tell them you hate it. Keep it to yourself. It only makes the author feel bad.
6. Don't review a story if you're just replying to a message. That's what the private messaging system is for.
7. Don't write a fic with all OCs and no real characters. That's what FictionPress is for.
8. We know you aren't perfect, and there will be mistakes in your stories. Please try to make it not so bad.
9. If you don't like the pairing, don't read it. It's as simple as that.
10. Don't be a review brat (I've been through this stage.) You shouldn't be writing for reviews but for the sole purpose of writing. If they really like you, they'll review.
11. Don't make the characters too OOC. The reason we love or hate them is because of who they are. Don't change them too much.
12. If someone's related to someone else, don't change that. The family tree should stay the same. If someone isn't related to someone, don't change that either!
13. Abandoned stories are okay, just tell the readers that you are abandoning it. That way you don't fill their heads with waves of hope.
14. Don't cyber stalk your favorite fanfiction author. You can read and review all their stories - they love reviews! - but don't continuously message them to update. They're trying as hard as they can!
15. Crack is good. Don't knock it until you try it.
16. Don't put in your profile that you hate yaoi or yuri. At least don't make it come off that you're a huge homophobe. You could hurt someone's feelings (not to mention come off really immature.) Just simply say that you will or won't write for it. Nothing more.
17. AU is okay as long as the characters are "in character." AU and OOC would basically be like writing your own story. For that you can actually make money. Ker-ching ker-ching!
18. Don't add FanFiction author to your facebook or myspace or other social network unless you really know them or have their permission.
19. Plot bunnies aren't evil, but don't have more than ten stories posted and running at the same time unless you're a really fast updater.
20. Alltho the awthor shuld chek four speling befor posteng, yoo shuldn't judje a storie on speling and gramar, ignor sum of thee mistakes becuz the storie may acchully be reely gud.
21. Lists like these? Don't put them in your favorite section unless it's completely relevant.
22. If you're going to PM someone, at least look at their stories.
23. You know, there's a hide bio button on every profile if you think it's too long.
24. Constructive criticism is not a flame. Constructive criticism is along the lines of, "I like this story, but I think this could make it better..."
25. Lastly, don't pick a story based on length. I know we all have no time on our hands, but you can take forever on a story if it's really good. Try to check out as many fics as you can.

These are my views on the common courtesy of a fanfiction author and reader. You can agree or not, but I could care less.