White hat methods of SEO involve following the search engines' guidelines as to what is and what isn't acceptable. Their advice generally is to create content for the user, not for the search engines; to make that content easily accessible to their spiders; and to not try to game the system. Often, webmasters make critical mistakes when designing or setting up their websites, inadvertently "poisoning" them so that they will not rank well. White hat SEOs attempt to discover and correct mistakes, such as machine-unreadable menus, broken links, temporary redirects, or a poor navigation structure.
Because search engines are text-centric, many of the same methods that are useful for web accessibility are also advantageous for SEO. A detailed case for this common ground, cited by the W3C with respect to Developing a Web Accessibility Business Case, is SEO A Positive Influence on Web Accessibility. Google has brought the relationship between SEO and accessibility even closer with the release of Google Accessible Web Search which prioritises accessible websites.
Methods are available for optimizing graphical content, including ALT attributes, and adding a text caption. Even Flash animations can be optimized by designing the page to include alternative content in case the visitor cannot read Flash.
Some methods considered proper by the search engines:
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