A Google employee's blog has revealed that the search firm has blacklisted BMW for trying to manipulate its ranking system, and that Ricoh will soon suffer the same treatment. 

Matt Cutts, who wrote Google's Safe search filtering feature, said in his blog that BMW.de created so-called 'doorway' pages which contravene Google guidelines.

A 'doorway' page contains a list of keywords designed to boost its position in the rankings, but then redirects users to a different site, in this case BMW's German sales site.

"That's a violation of our webmaster quality guidelines, specifically the principle of not deceiving your users or presenting different content to search engines than you display to users," wrote Cutts.

"It appears that at least some of the JavaScript redirecting pages have already been removed from BMW.de, which is very encouraging."

BMW.de will now have its popularity rating reduced to zero, the so-called 'Google Death Penalty', although the BMW.com URL is unaffected. Cutts warned that Ricoh.de is about to suffer the same fate.

Google is increasingly cracking down on practices designed to fool its search engine technology. It has published official webmaster quality guidelines to explain what is allowed and what is not. 

"If you work at a large company that has doorway pages, keyword stuffing, or other tricks against our webmaster quality guidelines in a non-English language, consider this a courtesy notice that Google will pay a lot more attention to spam in other languages in 2006," warned Cutts.

"Please check your site for issues now to avoid any potential problems."