I am trying to save the relative data about gp_Trsf into the OCAF. I have found TDataStd_CoordSys that can be done. Unfortunately, I find the TDataStd_CoordSys.cxx without TDataStd_CoordSys.hxx. In the TDataStd_CoordSys.cxx, there is TopLoc_location that is relative with gp_Trsf. Now, I am stuck. Does anyone give me any suggestion? Thanks a lot.