Quite a number of players play a double of an opening bid just shows values without any other good call available (this might even be the majority of players in certain tourneys). Others play the double as takeout, as recommended in all the books. However if you click on the double during online play to find out which type of double, both styles will describe their double as takeout. You could ask a long question like "does your double promise either a very big hand or at least three cards in each of the unbid suits?" but this would just slow the game down and might confuse the issue.
So I propose that the first style be termed a "fakeout" double, as one or more of the "outs" might be "fake" (shorter than three). For example a 2=3=4=4 shape double of a 1D opening would be a fakeout double. Now when you click on somebody's double, the doubler could just quickly reply takeout, fakeout, t/o, or f/o.
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