Nikon D6 Reference Manual page 947

Option
[List saved
values]
[Choose value
for current lens]
List values saved using
[Fine-tune and save
lens]. Highlighting a lens
in the list and pressing 2
displays a [Choose lens
number] dialog.
•
The [Choose lens
number] dialog is used to choose the lens
identifier. Choosing a unique identifier—such as
the last two digits of the lens serial number—helps
you distinguish between multiple lenses of the
same type.
•
With some lenses, the serial number will
automatically be entered as the lens identifier.
Choose from multiple fine-tuning values saved for
lenses of the same type.
Description
B The Setup Menu: Camera Setup 895