tedster - 6:23 pm on Apr 27, 2009 (gmt 0)

From the number of reports coming into the forum, it seems like there's been some jiggling going on in the SERPs recently - but I'm seeing even less ranking churn than usual.

Looks like there is a sub-index of pages per website. Anyone has ever heard of that ?

Observations such as yours, Cirilo007, are more common - disruption with the site: operator numbers.

Yes there definitely are "sub-indexes" - these grew out of Google's original Supplemental Index. There is some information about this in the Hot Topics area [webmasterworld.com], which is always pinned to the top of this forum's index page. There are also a few very recent threads that may be touching on the area. This discussion [webmasterworld.com] is one example.

Another thing to note is that the site: operator numbers are challenging for Google to report on accurately, because of the way their data is sharded. That's one of the reasons you usually see the word "about" before the number.