var golang.org/x/text/internal/language.altRegionIDs

2 uses

	golang.org/x/text/internal/language (current package)
		lookup.go#L233: 				return Region(altRegionIDs[i/3]), nil
		tables.go#L1142: var altRegionIDs = [11]uint16{

The pages are generated with Golds v0.7.6. (GOOS=linux GOARCH=amd64)