Cloaking (“Verschüllen”) is used in the area of search engine optimization (SEO) whenever a server plays a search engine crawler under the same URL a different version of the website than human visitors. The black hat method is used as a deliberate deception to improve the ranking of a website. Google and other search engine providers, therefore, rate this type of search engine optimization as a rule violation. However, a manipulation intention was not at the forefront of cloaking from the beginning.
Origin of The Cloaking Method
Web pages whose content consists primarily of graphics, videos or Flash animations usually do poorly in search results. Multimedia content, which may well be popular with many users, can only be read out in basic terms by text-based search engines. This deficit can be compensated for by cloaking: Instead of the original page, the search engine crawler is shown a description of the image and video contents and thus an HTML website in pure text form. Search engines can easily process such content and index the website accordingly. However, the selective output of various web page versions carries a high potential for abuse.
Cloaking As a Deception
Again and again, website operators use cloaking methods to present the search engine content that is not available to site visitors. Such a manipulation attempt can be illustrated by the example of a fictional casino website:
In order to increase the visibility on the World Wide Web, the provider of an online casino delivers targeted content to social games to a search engine crawler. This is despite the fact that only paid games of chance are available to visitors on the website. As a result, the search engine lists the online offer due to the wrong information in the parlor inde. And erroneously outputs the web page as the search result for corresponding keywords. The annoyed misguided visitor and reduces the user-friendliness of the search engine.
In order to prevent such tricks, search engine operators are taking a hard line against cloaking. Market leader Google maintains a specialized webspam team, especially for such cases. Website operators who use appropriate methods must expect their project to be completely removed from the search index (Google Penalty). The Webmaster Guidelines (Google Webmaster Guidelines) lists Google under concrete recommendations which methods should be avoided cloaking fourth on.
Web site operators using the Black Hat method typically use two different techniques to deceive search engines.
User Agent Cloaking (Agent Name Delivery)
Access to a website is usually via a so-called user agent. Examples of user agents are client applications such as web browsers or automated programs such as crawlers. These can be identified by a specific identifier, the agent name. This allows a web server to tailor requested content to the respective browser through optimized stylesheets, thus increasing the usability of a web page. Agent Name Delivery thus forms the basis for a device-optimized display, However, such a procedure becomes cloaked when web site operators integrate certain mechanisms that specifically respond to agent names of known web crawlers such as the Google bot and supply them with separate content. Therefore, to circumvent Agent Name Delivery, search engine providers sometimes disguise their web crawlers as ordinary browsers.
IP Cloaking (IP Delivery)
In addition to the agent name, the IP address offers a way to categorize website visitors. And provide them with special content. Among other things, the method is used in the context of geotargeting in order to play website visitors’ different language versions or regional offers. Cloaking becomes IP delivery when a website operator delivers customized content to the default IP address of a crawler. However, such a black hat SEO is only successful if the corresponding bot always uses the same IP address. To prevent this manipulation, most search engine providers now rely on changing IP addresses.
However, in an official video article on the topic, Matt Cutts, the former head of the Google Webspam team, emphasizes that IP-based geotargeting and customizing web page content to mobile user agents are definitely not cloaking, But rather desirable action User-friendliness are. Thus, it does not matter to Google whether a website visitor from France due to special language versions other content gets displayed than a German visitor, as long as the contents cover what a web crawler on the website finds.