CHAPTER VII
Proprieties 

LAW 75 - PARTNERSHIP AGREEMENTS 

A. Special Partnership Agreements

Special partnership agreements, whether explicit or implicit, must be fully and freely available to the opponents (see Law 40). Information conveyed to partner through such agreements must arise from the calls, plays and conditions of the current deal.

B. Violations of Partnership Agreements

A player may violate an announced partnership agreement, so long as his partner is unaware of the violation (but habitual violations within a partnership may create implicit agreements, which must be disclosed). No player has the obligation to disclose to the opponents that he has violated an announced agreement; and if the opponents are subsequently damaged, as through drawing a false inference from such violation, they are not entitled to redress.

C. Answering Questions on Partnership Agreements

When explaining the significance of partner's call or play in reply to an opponent's inquiry (see Law 20), a player shall disclose all special information conveyed to him through partnership agreement or partnership experience; but he need not disclose inferences drawn from his general knowledge and experience.

D. Correcting Errors in Explanation

1. Explainer Notices Own Error

If a player subsequently realises that his own explanation was erroneous or incomplete, he must immediately call the Director (who will apply Law 21 or Law 40C).

2. Error Noticed by Explainer's Partner

A player whose partner has given a mistaken explanation may not correct the error before the final pass, nor may he indicate in any manner that a mistake has been made; a defender may not correct the error until play ends. After calling the Director at the earliest legal opportunity (after the final pass, if he is to be declarer or dummy; after play ends, if he is to be a defender), the player must inform the opponents that, in his opinion, his partner's explanation was erroneous.

Example 1 - Mistaken Explanation
The actual partnership agreement is that 2 is a natural sign-off; the mistake was in North's explanation. This explanation is an infraction of law, since East-West are entitled to an accurate description of the North-South agreement (when this infraction results in damage to East-West, the Director shall award an adjusted score). If North subsequently becomes aware of his mistake, he must immediately notify the Director. South must do nothing to correct the mistaken explanation while the auction continues; after the final pass, South, if he is to be declarer or dummy, should call the Director and must volunteer a correction of the explanation. If South becomes a defender, he calls the Director and corrects the explanation when play ends.

Example 2 - Mistaken Bid
The partnership agreement is as explained - 2 is strong and artificial; the mistake was in South's bid. Here there is no infraction of law, since East-West did receive an accurate description of the North-South agreement; they have no claim to an accurate description of the North-South hands. (Regardless of damage, the Director shall allow the result to stand; but the Director is to presume Mistaken Explanation, rather than Mistaken Bid, in the absence of evidence to the contrary.) South must not correct North's explanation (or notify the Director) immediately, and he has no responsibility to do so subsequently.

In both examples, South, having heard North's explanation, knows that his own 2 bid has been misinterpreted. This knowledge is "unauthorised information" (see Law 16A), so South must be careful not to base subsequent actions on this information (if he does, the Director shall award an adjusted score). For instance, if North rebids 2NT, South has the unauthorised information that this bid merely denies a four-card holding in either major suit; but South's responsibility is to act as though North had made a strong game try opposite a weak response, showing maximum values.