ADG2128:signal input range for B grade


I am asked about signal input range for B grade ADG2128 from our customer.

In the table 2 of the datasheet (Rev.D), It is blank for Analog Signal Range for B grade.

( In Y grade, it is descibed  as "Vdd-2V")

I guess that the input range of B grade is same as Y grade, why is it blank for B grade ?

Best regards,