  Sum rules -- relating the static quark potential V(R) to the spatial
distribution of the action and energy in the colour fields of flux-tubes -- are
applied in three ways: 1) To extract generalised beta-functions: 2) As a
consistency check for the use of excited gluon flux-tubes and as an estimate of
the quark self-energies: 3) To extract approximate sum rules using a simplified
form of V(R). Also the flux-tube profiles are compared with hadronic string and
flux-tube models.
