Matt Cutts, Google Search Team. Jul 31, 2006.
Is my homepage in supplemental results?
Try this search (#1):
Code:
site:example.com -inallurl:example.com
These are the pages in Google's main index.
This search (#2):
...will show you all of your site's pages in Google's index.
With these 2 numbers, you can also calculate the "supplemental ratio", which is the percentage of pages on your site indexed by Google which are in the supplemental index.
How can I tell if a page is in supplemental results?
This is difficult to determine because Google wants to make it difficult for you to figure this out. Generally, it doesn't matter, but if you see a page appear in search #2 but not in search #1, then it's in the supplemental index.
How do I tell if the results of a search are supplemental?
Again, this is hard to tell. For multiple-word queries, it doesn't really matter. There's currently no direct way offered by Google to find this.