Adopted by IUGG 1967 Lucerne.  Inverse flattening given is derived from geocentric gravitational constant (GM)= 398603e9 m*m*m/s/s; dynamic form factor (J2) = 0.0010827 and Earth's angular velocity w = 7.2921151467e-5 rad/s. See also GRS 1967 (SAD69).