Quote
Effective Jan. 1, 2012, simple club responses to all natural notrump openings that ask for a major (four or more) are not Alertable. If you play Puppet Stayman (i.e. 1NT-2♣ or 2NT-3♣ to ask for a four-card or longer major), the club bids do not require an alert. All immediate responses and rebids to Puppet Stayman require an alert.
The required alert of Puppet has annoyed me for a very long time, as it allows pairs to "remember" whether they play puppet or not based on opener's alert (or non-alert). I think this change is a very good one that has been a long time in coming!
In general I have been quite critical of ACBL on alert and convention policy, and feel like I should balance the scales a bit by pointing out when they do something right.