Avoid expulsion from Google by following these SEO tips on what not to do. It’s very important that you obey the rules of the search engines or your site will be placed in a black hole.

Cloaking: A type of search-engine subterfuge in which an indexed Web page is not shown to visitors who click its link in Google (or another search engine). The cloaking works two ways: Visitor content is cloaked from Google, and Google’s indexed content is cloaked from visitors. This serves to give a high PageRank to content that ordinarily would rate a low PageRank. Cloaking is not always illicit. A certain type of cloaking are used to deliver pages tailored to a visitor’s ISP (America Online, for example) or specific Web browser.

Doorway page: An entry page to a Web site, sometimes known as a splash page. Doorway pages endure a negative connotation due to illicit techniques that send visitors to an entirely different site than the destination they clicked in Google.

Excessive Cross linking: When cross linking is done intentionally, the Webmaster is seeking to raise the PageRank of the involved sites. Excessive cross linking can backfire. If Google decides that the resulting enhanced PageRank is artificial, any or all of the sites might be expelled from the Web index. Innocent cross linking between two related sites is usually not a problem.

Keyword stuffing: The attempt to gain a higher PageRank (or higher ranking in any search engine) by loading a page’s HTML code or text with keywords. In most cases a visitor can’t see the keywords because they’re buried in HTML tags, camouflaged against the background color of the page, or reduced to a tiny typeface. Keyword stuffing violates Google’s guidelines for Webmasters and can result in expulsion from the index.

Link farm: A site whose only function is to display outgoing links to participating Web sites. Link farms are disreputable versions of legitimate, topical link exchange sites through which visitors gain some content value. Link farms often have no topicality and present no guidelines or standards of submission. Google does not explicitly threaten expulsion for joining link farms, but it discourages their use.

Mirror site: Mirror sites duplicate content and are used for both legitimate and engine-spamming purposes. Legitimate mirror sites assist in downloading when a great deal of traffic is trying to reach a page or acquire a file. Illicit mirror sites attempt to fill a search results page with multiple destinations owned by a single entity. When Google discovers a mirror site whose only purpose is to dominate a search page, that site risks expulsion.

Page redirect: A background link that sends site visitors to another site. Page redirects can be used legitimately, as when a site moves from one domain to another. In that scenario, the Webmaster sensibly keeps the old domain active for a while, seamlessly sending visitors to the new location when they click the old one. As an illicit optimization technique, page redirects deflect visitors from the site indexed by Google to another site that would not be able to gain as high a PageRank. This type of redirect, when uncovered by Google, risks the expulsion of both sites from the index.

Spam: Generally refers to repeated and irrelevant content. As an optimization term, spam refers to loading a page with keywords or loading a search engine’s index with mirror sites. Google reacts strongly to spamming, and takes harsh measures against Web sites that use spamming techniques to improve PageRank.