  A computation of the NRQCD $\beta$ function both in the Lorentz gauge family
and in the Coulomb gauge to one loop order endorses a velocity power counting
scheme for dimensionally regularised NRQCD. In addition to the ultrasoft scale
represented by bremsstrahlung gluons and the potential scale with Coulomb
gluons and on-shell quarks, a soft r\'egime is identified in which energies and
momenta are of order $Mv$, gluons are on shell and the quark propagator becomes
static. The instantaneous gluon propagator has a non-zero vacuum polarisation
only because of contributions from this r\'egime, irrespective of the gauge
chosen. Rules are derived which allow one to read up from a given graph whether
it is zero because of the homogene{\ia}ty of dimensional regularisation. They
also apply to threshold expansion and are used to prove that ultrasoft quarks
with energy and momentum of order $Mv^2$ decouple from the theory.
