error 406 Document not acceptable to client

[LuckyShima]

Error hits for "406 Document not acceptable to client" have jumped 20 times from November to December for a couple of similar sites.

Does anyone have any experience with what this might be referring to?

Thanks.

[James]

My guess is that it's likely just people trying to view a filetype which their browser doesn't understand or there's some sort of spider that's accessing your website and it's 'stupid,' trying to access files which aren't web pages.