aircraft approach category quandary

I know the aim para 5.4.7 says that aircraft approach categories are
based on 1.3 times the stall speed in the landing config at max
certificated gross landing weight (comes from far 97.3 (b).

However I know I have read somewhere, perhaps the aim or a far,
something along the lines that where the manufacturer has provided
data to allow the pilot to determined the approach speed based on
weight, that this can then be used to determine which category the
aircraft falls in.

Does anyone know of where I would have read something along these
lines?

Stan