lucy24 - 11:42 pm on Mar 12, 2013 (gmt 0)
excluded by x-robots-tag headers and robots.txt
Now, wait, that's something entirely different. Something it took me years to wrap my head around, in fact ;)
robots.txt prevents crawling. It doesn't prevent indexing.
I recently had to add a line of text to my test site's front page saying something like "sorry, folks, there's nothing here". The entire domain is roboted-out. So when a search query points straight to the domain name, it will show up in search results as a listing without a text snippet.