CHAPTER V
THE AUCTION 

PART I
CORRECT PROCEDURE

SECTION ONE
AUCTION PERIOD

LAW 20 - REVIEW AND EXPLANATION OF CALLS 

A. Call Not Clearly Heard

A player who does not hear a call distinctly may forthwith require that it be repeated.

B. Review of Auction during Auction Period

During the auction period, a player is entitled to have all  previous calls restated when it is his turn to call, unless he is required by Law to pass; Alerts should be included in the restatement.

C. Review after Final Pass

1. Opening Lead Inquiry

After the final pass either defender has the right to ask if it is his opening lead (see Law 47E and Law 41).

2. Review of Auction

Declarer or either defender may, at his first turn to play, require all  previous calls to be restated (see Law 41B and Law 41C).

D. Who May Review the Auction

A request to have calls restated shall be responded to only by an opponent.

E. Correction of Error in Review

All players, including dummy or a player required by Law to pass, are responsible for prompt correction of errors in restatement (see Law 12C1 when an uncorrected review causes damage).

F. Explanation of Calls

1. During the Auction

During the auction and before the final pass, any player, at his own turn to call, may request  a full explanation of the opponents' auction (questions may be asked about calls actually made, or about relevant calls available but not made); replies should normally be given by the partner of a player who made a call in question (see Law 75C).

2. During the Play Period

After the final pass and throughout the play period, either defender at his own turn to play may request  an explanation of opposing auction. At his or dummy's turn to play, the declarer may request an explanation of a defender's call or card play conventions.

Law 16 may apply; and sponsoring organisations may establish regulations for written explanations.