Search neutrality is a principle that search engines should have no editorial policies other than that their results be comprehensive, impartial and based solely on relevance. This means that when a user types in a search engine query, the engine should return the most relevant results found in the provider's domain (those sites which the engine has knowledge of), without manipulating the order of the results (except to rank them by relevance), excluding results, or in any other way manipulating the results to a certain bias.