  First-order phase transitions (PTs) with more than one globally conserved
charge, so-called noncongruent PTs, have characteristic differences compared to
congruent PTs (e.g., dimensionality of phase diagrams and location of critical
points and endpoints). Here we discuss the noncongruent features of the QCD PT
and compare it with the nuclear liquid-gas (LG) PT, for symmetric and
asymmetric matter in heavy-ion collisions and neutron stars. In addition, we
have identified a principle difference between the LG and the QCD PT: they have
opposite slopes in the pressure-temperature plane.
