The term cloaking,
considered a form of spam by search engines, is the technique
of hiding true page content from either a human or robot
visitor. This technique is used both to camouflage actual
page content from page thieves and to artificially present
a more “search engine friendly” website to
visiting spiders. Cloaking is considered an unacceptable
practice by all of the major search engines and can be
cause for banning.
See also SEM Glossary