Kloaking (cloaking, (English; a computer.) masking, concealment) - a way of concealment of "black" methods of optimization, by delivery to usual visitors of the version of page distinct from what receives the robot of the search engine to the same address. Kloaking it is realized exclusively with use of server scripts. Thus, the simple visitor sees usual page, and the search robot - specially modified, with the purpose as much as possible to raise{increase} relevance of page on the certain searches. The modified version of page usually has inconvenient for perception{recognition} the person appearance.

Methods kloakinga can be used and in the "peace" purposes. For example, for delivery of variants of pages in different languages, or the pages adapted to viewing by certain browsers.

Such application kloakinga is not considered kriminal`nym and is not punished by search machines.

On methods of job kloaking it is possible to divide{share} into three groups:

?         kloaking on User-Agent it is used both at a deceit of search machines, and in "peace" variants. The script compares field User-Agent of the come visitor to beforehand generated list of values deciding{solving}, what variant of page to show this time;

?         kloaking on IP it is used both at "black" methods of optimization, and in "peace" variants.

Comparison of the IP-address of the visitor with beforehand generated table the script calculates, what variant of page to show the given visitor;

?         kloaking on other fields of search it is used most less often and extremely in the peace purposes.

For example, using field Accept-Language it is possible to define{determine} preferable language of the visitor.