  Let M be a smooth compact manifold without boundary. We consider two smooth
Sub-Semi-Riemannian metrics on M. Under suitable conditions, we show that they
are almost conformally isometric in an Lp sense. Assume also that M carries a
Riemannian metric with parallel Ricci curvature. Then an equation of Ricci
type, is in some sense solvable, without assuming any closeness near a special
metric.
