A WebmasterWorld thread uncovers a very interesting occurrence that is taking place when using a site command feature, known as the “hidden” or “invisible” site command search.
If you want to search with a site command but don’t want the referral data to show that you are using a site command while searching, you use to be able to use a flavor of a Google Custom Search Engine to get at it. The example given is:
Notice that when you search using that command, up come videos from YouTube.com or video.google.com, included in the webmasterworld.com results. A site command is suppose to restrict the results, only to results from that site, i.e. webmasterworld.com.
The same issue happens when you change it to sitesearch=seroundtable.com. But it is not an issue when using the Google Custom Search Engine that I placed on this site, see here.
At first, I thought it may be an issue with Google Custom Search Engines. Because last night, TechCrunch reported that there was a major outage with the Google CSE. But Google said they fixed that, so that is not the issue.
Maybe the thread creator is right:
Who knows, maybe this is the wrong query string in the first place?
Forum discussion at WebmasterWorld.