In England all calls that are not natural require an alert. As a result, an Acol 2
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opening and an artificial 2
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response thereto are alertable.
However, it is difficult to see how the opponents are going to be damaged if someone forgets.
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Note that discussions are underway for the next Orange book, and there is a feeling that after fifteen years of unchanged alerting, the time may have come for sweeping changes because the game has changed so much.