Sample Data: Belgian Datum 1972 <-> WGS84 
    
    |  |  | 1) | 2) | 3) | 
    
    | BD 72 
    (Hayford) | lat. lon. | 51°18'39".48882 N 3°10'03".41519 
    E | 51°08'10".75864 N 5°27'47".75844 
    E | 50°29'57".14179 N  4°03'01".99697 
    E | 
    
    | WGS84 
    Ellipsoid | lat. lon. | 51°18'37".60145 N 3°10'07".86956 
    E | 51°08'08".80587 N 5°27'52".44192 
    E | 50°29'55".15235 N 4°03'06".50275 
    E  | 
References
NGI/IGN-B June 1999.
http://www.ngi.be/HTML-files/dutch/0038.htm(dutch)
http://www.ngi.be/HTML-files/french/0038.htm(french)