Quality guidelines

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?"