Zero-click Info (?)
The referrer, or HTTP referrer—also known by the common misspelling referer that occurs as a HTTP header field—identifies, from the point of view of an internet webpage or resource, the address of the webpage of the resource which links to it. More at
Wikipedia
Referrer spoofing, changing referrer information to gain unauthorized access to a web site.
Referrer spam, providing fake referrer information in order to popularize a spammer's website.
