Don't be an Ass:
Boasting OOC of your exploits can be fun, rewarding and enjoyable, even to other people when done tastefully. However, laughing to another player about how much you screwed over their character makes you an ass. Cackling to another player about how much you will fuck their character makes you an ass. Nominating another player at game end for "being a hardcore noob" makes you an ass that will get a dot of "kicked in the teeth by exasperated STs." Don't be an ass.
How to play well with others:
IC Downtime Actions are Never Required:
Players are not obligated to put in any additional work into the game on top of the time players already devote to being online. If you wish to run downtime scenes involving another character, and that character's player is unable to attend them, such scenes either do not take place or the players may agree to an acceptable IC reason why the character is absent. Players who do not wish to receive e-mails sent IC may justifiably do so, claiming that they don't have voice-mail, e-mail, a mailing address, or that their IC communications equipment is simply on the fritz. In short, be considerate of the fact that some people have real lives during the rest of the week and don't want to play 24/7. The forums are a good place to contact players and have conversations slower then the fast paced mIRC time frames.
OOC Planning is Never Required:
Planning and strategizing OOC with other players for game and assuming your characters have IC conversations to back it up often borders on meta-gaming and can decrease the flavor of the game. This being said, if you wish to make plans OOC, all parties involved must consent to running planning OOC, and any player involved may request that an IC scene take place instead. Running the scene IC leaves no questions on what people know IC instead of just OOC! It helps everyone! E-mails sent OOC are to be interpreted as OOC missives, and players who do not wish to regard them as IC missives are under no obligation to do so.
Newbs are to be treasured:
Don't pick on new players, who, due to inexperience with game or unfamiliarity with pirates have less of a grasp of what's going on in the game world. Even if it might be reasonable for your character to kill their characters, take advantage of their characters, it's generally best to leave off until the *players* are at a point where they've learned the ropes. Seriously, we need these people to come back. Also, don't hestitate to play with newbs because they're outside your clique. New players often bring fresh and interesting ideas to a game.
No Puppy-Raping Without Consent:
Some topic matter that may well reasonably appear in the setting may make some players uncomfortable. They may well make some STs uncomfortable. Explicit sex, rape, incest, pedophillia, torture, beastiality and other "iffy" topics should generally require the consent of other players involved in a scene before being introduced into it. If you wish to run scenes involving said topics with an NPC, it is generally wisest to go to an ST directly.
Don't Screw Over Others if They Have to be Absent:
With the above rule in mind, it's generally in bad form to take undo advatage over a PC's absence due to their player's absence. While extended absences with no explanation can naturally lead to a PC's power vacuum being filled, it's best to lay off if the player has had to miss one game due to extenuating circumstances.