  In the last years measure-valued solutions started to be considered as a
relevant notion of solutions if they satisfy the so-called measure-valued --
strong uniqueness principle. This means that they coincide with a strong
solution emanating from the same initial data if this strong solution exists.
This property has been examined for many systems of mathematical physics,
including incompressible and compressible Euler system, compressible
Navier-Stokes system et al. and there are also some results concerning general
hyperbolic systems. Our goal is to provide a unified framework for general
systems, that would cover the most interesting cases of systems, and most
importantly, we give examples of equations, for which the aspect of
measure-valued -- strong uniqueness has not been considered before, like
incompressible magentohydrodynamics and shallow water magnetohydrodynamics.
