Ok I now the problem. The classification came from the X-games (X-BtF, X-T, X2 The Threat, X3 Reunion, X3 Terran Conflict, X3Albion Prelude, X Rebirth).
M0-M5 from the first two games, M6 (Corvettes) are implementet with X2, and M7 (Frigates)/M8 (Bombers) with X3 Terran Conflict.
And the...