  We give a complete classification of T6/[Z(2)xZ(2M)xOmegaR] orientifolds on
factorisable tori and rigid D6-branes on them. The analysis includes the
supersymmetry, RR tadpole cancellation and K-theory conditions and complete
massless open and closed string spectrum (i.e. non-chiral as well as chiral)
for fractional or rigid D6-branes for all inequivalent compactification
lattices, without and with discrete torsion. We give examples for each orbifold
background, which show that on Z(2)xZ(6) and Z(2)xZ(6') there exist completely
rigid D6-branes despite the self-intersections of orbifold image cycles. This
opens up a new avenue for improved Standard Model building. On the other hand,
we show that Standard and GUT model building on the Z(2)xZ(4) background is
ruled out by simple arguments.
