OpenGL spec - ref man mismatch?

GL_SPOT_DIRECTION parameter of glLight function contains 3 integer or
floating point values that specify the direction of the
light in Homogeneous Object Coordinates. There is a contradiction on
the way of implementation of this parameter in
OpenGL Reference Manual(Blue Book) and OpenGL Spec 1.2.1.
_SPOT_DIRECTION is said to be transformed by the
inverse of the Modelview Matrix by OpenGL Reference Manual (Blue Book
Version 1.4, glLight, page 374).
However, The OpenGL Spec 1.2.1 says that GL_SPOT_DIRECTION is
transformed using only the upper leftmost 3x3
portion of the Model-view matrix, that is by Mu. (Spec 1.2.1; 2.13.2
Lighting Parameter Specication; page 49).

In the code, the Blue Book approach is taken into consideration and
GL_SPOT_DIRECTION is multiplied by the inverse
of the Model-view Matrix. Which approach shall be taken as correct approach?

The one that works.