Google Supplemental Index is NOT a place you want to be! The way you end up in there is if your pages are so badly described or categorised, Google could scarecely decide if there was a difference between them. Bottom line is, if you don't take the time and effort to make your pages unique, with page URLs, Titles and Descriptions that accurately describe the contents of the page, why on earth should Google even bother indexing them at all? That they do so is a credit to them, even though they no option but to park them in the "Other Crap We Found" bin...