Search Engine guidelines are very specific and do not leave any gray area that would be open to multiple conclusions. Google search engine, Yahoo! search engine, MSN search engine and AOL search engine are very specific in what they do and don't allow when optimizing a website.

Design and content guidelines

• Make a site with a clear hierarchy and text links. Every page should be reachable from at least one static text link.
• Offer a site map to your users with links that point to the important parts of your site. If the site map is larger than 100 or so links, you may want to break the site map into separate pages.
• Create a useful, information-rich site, and write pages that clearly and accurately describe your content.
• Think about the words users would type to find your pages, and make sure that your site actually includes those words within it.
• Try to use text instead of images to display important names, content, or links. The Google crawler doesn't recognize text contained in images.
• Make sure that your <title> elements and alt attributes are descriptive and accurate.
• Check for broken links and correct HTML.
• If you decide to use dynamic pages (i.e., the URL contains a "?" character), be aware that not every search engine spider crawls dynamic pages as well as static pages. It helps to keep the parameters short and the number of them few.
• Keep the links on a given page to a reasonable number (fewer than 50).

Technical guidelines

• If fancy features such as JavaScript, cookies, session IDs, frames, DHTML, or Flash keep you from seeing all of your site in a text browser, then search engine spiders may have trouble crawling your site.
• Make use of the robots.txt file on your web server. This file tells crawlers which directories can or cannot be crawled. Make sure it's current for your site so that you don't accidentally block search engine crawler. Visit http://www.robotstxt.org/faq.html to learn how to instruct robots when they visit your site.
• Test your site to make sure that it appears correctly in different browsers.

Quality guidelines

These quality guidelines cover the most common forms of deceptive or manipulative behavior, but search engines may respond negatively to other misleading practices not listed here (e.g. tricking users by registering misspellings of well-known websites). It's not safe to assume that just because a specific deceptive technique isn't included on this page, search engines approves of it.

Quality guidelines - basic principles

• Make pages primarily for users, not for search engines. Don't deceive your users or present different content to search engines than you display to users, which is commonly referred to as "cloaking."
• Avoid tricks intended to improve search engine rankings. A good rule of thumb is whether you'd feel comfortable explaining what you've done to a website that competes with you. Another useful test is to ask, "Does this help my users? Would I do this if search engines didn't exist?"
• Don't participate in link schemes designed to increase your site's ranking or PageRank. In particular, avoid links to web spammers or "bad neighborhoods" on the web, as your own ranking may be affected adversely by those links.
• Don't use unauthorized computer programs to submit pages, check rankings, etc. Such programs consume computing resources and violate our Terms of Service. Search engines do not recommend the use of products such as WebPosition Gold™ that send automatic or programmatic queries to search engines.

Quality guidelines - specific guidelines

• Avoid hidden text or hidden links.
• Don't use cloaking or sneaky redirects.
• Don't send automated queries to Google.
• Don't load pages with irrelevant keywords.
• Don't create multiple pages, sub domains, or domains with substantially duplicate content.
• Don't create pages with malicious behavior, such as phishing or installing viruses, trojans, or other badware.
• If your site participates in an affiliate program, make sure that your site adds value. Provide unique and relevant content that gives users a reason to visit your site first.