  A direct connection between physical parameters of general Two-Higgs-Doublet
Model (2HDM) potentials after electroweak symmetry breaking (EWSB) and the
parameters that define the potentials before EWSB is established. These
physical parameters, such as the mass matrix of the neutral Higgs bosons, have
well defined transformation properties under basis transformations transposed
to the fields after EWSB. The relations are also explicitly written in a basis
covariant form. Violation of these relations may indicate models beyond 2HDMs.
In certain cases the whole potential can be defined in terms of the physical
parameters. The distinction between basis transformations and
reparametrizations is pointed out. Some physical implications are discussed.
