Crv Textures? | Animal Crossing New Horizons

[ninetalescommander]

So I checked out the models for Blathers and Rover (Thanks Ziella by the way) and I notice there are these textures called "Crv". I have to be honest; I've never come across textures like these before and have no idea how to apply them in the node editor in Blender. I know they are obtained from Alpha Channel on the Alb Texture so I figured they were some sort of alpha texture but I've had no joy figuring out how they work.

Anyone know? If you have not seen them for yourself, here's a link