Most engines also support multiple-word queries. More specific queries will enhance the relevance of the user's results. The final step is the search, locate, and match process itself. Location and frequency of the keywords' occurrence within the document are the most common criteria used by search engines in matching and ranking. Words located in the title of a document are awarded a greater weight, as are words located in HTML meta tags.
Most search engines recognize and defend against a practice called spamdexing.
The actual content may not be relevant. The most common practice is to simply overload the web page with common terms in the initial part of the document, in a way that is invisible to the user but readable by the search engine spider and index program. The detection of spamdexing by search engines will cause most to either omit the site from its results or to rank it at the bottom. A subject directory does not visit the web, at least not by using the programmed, automated tools of a search engine. Websites must be submitted to a staff of trained individuals entrusted with the task of reviewing, classifying, and ranking the sites.