A player should maintain at all times a courteous attitude toward both his partner and his opponents. He should carefully avoid any remark or action that might cause annoyance or embarrassment to another player or his partner, or any remark or action that might interfere with the enjoyment of another player of the game.

Conduct: to comport (oneself) in a specified way.   a mode or standard of personal behavior especially as based on moral principles.   way of acting; bearing or deportment. Synonyms: deportment, demeanor, manner, behavior    

As a matter of courtesy, a player, by the Laws of Duplicate Contract Bridge, should refrain from:

1. paying insufficient attention.
2. making gratuitous comments during the play as to the auction or the adequacy of the contract.
3. detaching a card from his/her hand before it is his/her turn to play.
4. concealing his/her cards from the sight of other players.
5. arranging the cards he/she has played to previous tricks in a disorderly manner or mixing his/her cards together before the result of the deal has been agreed upon.
6. prolonging the play unnecessarily.
7. making a questionable claim or concession.
8. using different designations for the same call when not using bidding boxes.
9. indicating any approval or disapproval of a call, bid or play.
10. indicating the expectation or intention of winning or losing a trick before play to that trick has been completed.
11. commenting or acting during the auction or play to call attention to a significant incident thereof, or to the state of the score, or to the number of tricks that will be required for success.
12. looking intently at any other player during the auction or play, or at the hand of another player for the purpose of seeing his/her cards or observing the place from which he/she draws a card.
13. varying the normal tempo of bidding or play for the purpose of disconcerting the other players.
14. leaving the table needlessly before the round is called.