That's what they say about META tag that allows tell google when a page should be removed from the main Google web search results. For example, to specify that an HTML page should be removed from the search results after 3pm Eastern Standard Time on 25th August 2007, simply add the following tag to the first section of the page: <META NAME="GOOGLEBOT" CONTENT="unavailable_after: 25-Aug-2007 15:00:00 EST">
I doubt very seriously that this is the robots tag that the original poster is speaking of. Perhaps but I doubt it. When people say "robots tag" they are generally referring to the meta robots tag... which can have values like: <meta name="robots" content="index, follow"> (default if NO robots tag) <meta name="robots" content="index, nofollow"> <meta name="robots" content="noindex, follow"> <meta name="robots" content="noindex, nofollow"> The noindex tells the search engines NOT to index the page. The noindex will cause Google to deindex the page. The nofollow is a page level nofollow, indicating that ALL outbound links on the page (to internal and external pages) are to be nofollowed.
Never heard of x or y referenced to robots - x any y are coordinates related to location on a web page. Best you supply some sample code here.
A robot tag in a web page may take the values index, noindex, follow, nofollow. This has been explained clearly with syntax by Canonical. I think that is what you mean when you say 'x robot tag' . Because I am not sure and I have never come across a robot tag called 'x' per se.