Nikon D6 Reference Manual page 1096

A
Recognizing CPU and Type G, E, and D Lenses
q
CPU lenses can be identified by the presence of CPU contacts ( ). Type G
lenses are marked with a "G", type E lenses with an "E", and type D lenses
with a "D". Type G and E lenses are not equipped with a lens aperture ring
( w ).
CPU lens Type G or E lens Type D lens
1044 Compatible F Mount Lenses