There's nothing stronger than a 404, is there? I wish I had a way to tell msnbot-media that
#1 I do not have a file called /templates/blahblah/images/iranian-barcode.png * nor yet any of the half-dozen similarly named image files you requested in the same 24-hour period. #2 I have never had a file called /templates/blahblah/images/iranian-barcode.png et cetera. #3 I never will have a file called /templates/blahblah/ et cetera. #4 You have clearly fallen prey to some variety of attempted hotlinking or robotic hiccup, and I want nothing to do with it.
I really hope they don't make a habit of this. Once bing/msn has taken it into its head that a particular file exists-- or used to exist-- or will come into existence at some point prior to the heat-death of the universe-- no power on earth will make them stop asking for it.
:: sigh ::
* Key element of urlpath obfuscated. Search for "blahblah" strongly suggests a specific domain, apparently Iranian, which I do not propose to visit. Not even with Lynx. Cursory further investigation via free lookup turns up the names "OVH" (registrar) and "Hetzner" (server). You can't make this stuff up.
The requested resource is no longer available at the server and no forwarding address is known. This condition is expected to be considered permanent. Clients with link editing capabilities SHOULD delete references to the Request-URI after user approval. If the server does not know, or has no facility to determine, whether or not the condition is permanent, the status code 404 (Not Found) SHOULD be used instead. This response is cacheable unless indicated otherwise.
The 410 response is primarily intended to assist the task of web maintenance by notifying the recipient that the resource is intentionally unavailable and that the server owners desire that remote links to that resource be removed. Such an event is common for limited-time, promotional services and for resources belonging to individuals no longer working at the server's site. It is not necessary to mark all permanently unavailable resources as "gone" or to keep the mark for any length of time -- that is left to the discretion of the server owner.
You should draw bing's attention to this passage. When I 410 a page, google quickly stops asking for it, but bing keeps requesting it faithfully for years to come. (Won't look it up, but I believe their current record is January 2011.)
Besides, I refuse to serve a 410 for a page that never existed in the firsst place. That's just encouraging them :)