“…Over F = R, the minimal orbit in U (2, 1) is Rdistinguished but not admissible. In general, the R-distinguished orbits for semi-simple groups are classified in [51, (under the name compact orbits), and comparing this classification with the classification of admissible orbits given in [50,Theorem 3] for classical groups, and [47,48] for exceptional groups, we see that for the groups (6.3) SU(p, q)(with p, q 1), EII, EV, EVI, EVIII, EIX there exist R-distinguished non-admissible orbits (1) . On the other hand, for other real simple groups, all R-distinguished orbits are admissible.…”