  This theoretical paper discusses microscopic models giving rise to special
types of order in which conduction electrons are bound together with localized
spins to create composite order parameters. It is shown that composite order is
related to the formation of a spin liquid with gapped excitations carrying
quantum numbers which are a fraction of those of electron. These spin liquids
are special in the sense that their formation necessarily involves spin degrees
of freedom of both the conduction and the localized electrons. A detailed
description of such spin liquid states is presented with a special emphasize on
a demonstration of their robustness against local perturbations preserving the
Lie group symmetry and the translational invariance.
