These lenses are for Minolta FILM cameras.
They do NOT fit Maxxum.
They do NOT fit Sony Alpha.
MC means the lens has 1 meter coupling lever. These lenses will work on the X series FILM cameras just fine but will not work on the X camera program setting.
MD means the lens has 2 meter coupling levers and will work on all the Minolta FILM cameras. The extra meter coupling lever works on the program setting for the X series cameras.