In England all calls that are not natural require an alert. As a result, an Acol 2
opening and an artificial 2
response thereto are alertable.
However, it is difficult to see how the opponents are going to be damaged if someone forgets.
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.