Clocking is a Controversial SEO technique. What does it involve?

[Amit]

Clocking is a Controversial SEO technique. What does it involve?
a-Increasing the keywords density on the WebPages
b-Offering a different set of WebPages to search engine
c-Hiding the keywords within the WebPages
d- Creating multiple pages and hiding them from the website Visitor

[Aditya]

Cloaking is a black hat SEO technique in which the content presented to the search engine spider is different from that presented to the user's browser. Different Cloaking Methods are:
IP address Cloaking
User-Agent Cloaking
HTTP_REFERER Header Cloaking
JavaScript Cloaking

[SEO PALM]

Cloaking is a SEO technique characterized as Black Hat SEO Techniques. This is done by the helping by .htaccess file and also by ip masking... and you can also use some script for cloaking a website's urls...