I guess the first thing is to explain what supplemental results were. In laymen terms supplemental results are pages that Google keeps in a separate index. They were identified in the SERPS as supplemental when those pages came up in a search. I’m sure Yahoo, MSN, and Ask have something similar. The difference is they are not as open with https://www.jaguarpc.com/wp-content/uploads/2024/06/jag-cloud-vps-hosting-1.pngs as Google is trying to be.
To me it was no big deal to have pages show as supplemental. In fact I have seen pages that were listed as supplemental out rank my pages which were were not supplemental. To those involved in the Search Engine Optimization Industry it was a big deal. Those people did not like having pages in the supplemental results. SEO’s saw the supplemental results as a road map telling them which pages on their site needed more work.
I’m not sure when Google started showing supplemental results. I think it was sometime in 2006. However, as Brett pointed out in his article 7 SEO Techniques That Google Smashed in 2007 Google has quit showing supplemental results in 2007. Man that caused an uproar.
At some point someone discovered a operator which they believed would show only supplemental pages. Brett mentions that in his article. The operator was “site: *** -sljktf” command (to show the supplemental index results).
Some people thought you could still discover supplemental pages with the operator, even after Google stopped showing supplemental results . Personally I don’t think the operator was broke. I don’t think it was ever accurate.