1. Alerting Procedure 

During the auction, explanations or comments should not be volunteered unless the opponent whose turn it is to call or play requires one. 

If an alert is not made promptly,  a non-offender is able to change a call made prior to the alert (but on condition that partner has not called subsequently). 

A belated alert or failure to alert constitutes misinformation and, if damaged, the nonoffenders may claim an adjusted score. 

A Player whose conventional call or special treatment has not been alerted by partner should not make any attempt to alert the opponents until the close of the auction. Before the opening lead is made, dummy or declarer should call the Director and inform the opponents of the failure to alert. However, a member of the defending side must wait until the conclusion of play, summon the Director and draw attention to partner’s failure to alert

2. Enquiries 
Upon enquiry about partner’s call or play from an opponent, whose turn it is to call or play, a Player must give a full and clear explanation of the partnership’s agreement (if there is one) or any information available to him/her through partnership experience. Questions about calls that were available, but not made, may also be asked. (Players should be aware that such questions may convey unauthorised information .) 
3. General Recommendations 
(a) Enquiries should be kept to a minimum and preferably deferred until the end of the auction. 

(b) In tournaments,Directors should insist on the use of System Cards to obviate the need for unnecessary enquiries. 

(c) Players should not enquire about calls that are normally natural unless alerted. (Such enquiries may constitute unauthorised information.) 

(d) If the enquirer does not understand an explanation, he/she is entitled to seek further clarification and should call the Director if a clear explanation is not forthcoming. 

4. Explanations 
Upon enquiry from an opponent whose turn it is to call or play, a Player must give a full and clear explanation of the partnership’s agreement (if there is one) as to the meaning of a call or play made by his/her partner. The explanation should include all specifications for the call or play including range of high-card strength, distribution, suit quality or any other relevant features explicitly agreed by the partnership.
  
Players should provide explanations only for those conventions that the partnership has previously discussed.

Where there is no explicit agreement, the Player should say so and should not "invent" an explanation or state a meaning that has been inferred from the evidence of the bidding, the hand held or general bridge experience. Recommended formula. "We do not have an explicit agreement". When stating that there is no explicit agreement, it is proper to describe the partnership's methods in similar situations. 
Even when it is apparent that partner has departed from the partnership's agreed methods (e.g. when his bid indicates a solid suit but his partner's hand holds a high honour card in the suit), the agreed meaning of the bid should be explained with no hint that anything is amiss. 
It is improper for a Player to take advantage of any information conveyed by partner's explanation. 
A Player should not volunteer any uninvited explanations of a call or play by partner.

 .