I looked at the datasheet for the pots we provide and there is no drawing of the specific curve for the pot, but there is a standard audio taper curve for a logarithmic potentiometer (type A).
A manufacturer of stepped attenuators should know this and should not be asking these questions of you (in 25 years of doing this, this is the first time I can recall something like this coming up). There's potentially a red flag here, proceed with caution!