(I first noticed this on Tuesday, but held off posting in case it was a temporary glitch. A couple days later, I’m assuming it’s not.)

It looks to me like the “show all your Google supplemental results” query is broken. As a reminder, this kind of query is supposed to show only results from Google’s supplemental index:

site:domain.com *** -asdfgh

From what I’m seeing on several domain queries, you get the same amount of results on that type of query that you get with a standard site: query. Here are examples:

Standard site: Query

Supplemental site: Query

Those two numbers should not be the same. Note: On the supplemental query, you may first only get shown a handful of results, i.e., “1-4 of 4.” But if you click the “show omitted results” link, you end up getting the same number of results as the standard site: query.

To my knowledge, this was never an official Google search operator. But unless I missed the news, it looks like they’ve disabled this and made it impossible for us to see a site’s supplemental results.

(Did I miss the news somewhere else?)

Update: Thanks to Michael & Michael in the comments, this appears to only be happening at some Google data center(s). Yet I’ve been hitting the ‘broken’ data center for three days running now….