Hi mate, mines labelled IG as is the rear dérailleur and cassette but I've got no idea what order Shimano made HG/IG in (I actually thought HG came first but like I said I'm no expert!).
My crankset has the inner bolts going through the small and middle chain rings into the crank arm then the outer ring bolts to the middle. Hope that helps!
Cheers,
Al
P.s. I no longer need a 32t chainring, thanks!