  We show that microscopic black hole entropy formula based on Virasoro algebra
can be derived from usual properties of stationary Killing horizons alone and
absence of singularities of curvature invariants on them. In such a way some
usual additional assumptions are shown to be fulfilled. In addition, for all
quantities power expansion near horizon and thus explicit insight of the
limiting procedure is given. More important the near horizon conformal symmetry
proposed by Carlip together with its consequences on microscopic entropy is
given a clear geometric origin.
