I have their Professional Product Guide which is helpful ... I guess what doesn`t make a lot of sense is something like this in their Traditional Paint Cleaners/Compounds:
#2 is Fine Cut Cleaner
#1 is Medium Cut Cleaner
#4 is Heavy Cut Cleaner
Most products, like sandpaper are numbered according to abrasiveness
80 grit is course
220 grit is medium
400 grit is fine ...etc.
So wouldn`t it make more sense to the consumer to number polishes according to abrasiveness ...
1 could be fine
2 could be medium
3 could be heavy ... but wait 3 is a machine glaze ... so
4 could be heavy
Oh well ... that is why I have the book