  Characteristic uncertainty relations and their related squeezed states are
briefly reviewed and compared in accordance with the generalizations of three
equivalent definitions of the canonical coherent states. The standard SU(1,1)
coherent states are shown to be the unique states that minimize the
Schroedinger uncertainty relation for every pair of the three generators and
the Robertson relation for the three generators. The characteristic uncertainty
inequalities are naturally extended to the case of several states. It is shown
that these inequalities can be written in the equivalent complementary form.
