Indirect squeezes are those in which at least one menace is a discovered or dual menace (that is, a menace in which it takes the combined resources of both opponents to prevent the development of an extra trick). If only one player is squeezed, the menace is discovered; if the squeeze is bilateral, the menace is dual.
Quite a few discovered and dual menaces are possible. To aid in the classification, we will divide them according to whether the menace is balanced (both opponents hold the same length in the suit) or unbalanced, and also according to whether the squeezer must lose a trick in the suit after the opponents have discarded from it (secondary if one or more tricks must still be lost, primary otherwise). Although eache type of menace has its own peculiarities, menaces in the same family do share some common structural features which are reflected in the types of squeezes supported by these menaces.