Overview#HTTP Referer is a HTTP Request Header contains the address of the previous web page from which a link to the currently requested page was followed.
Note that referer is actually a misspelling of the word "referrer"
HTTP Referer has the potential to reveal information about the browsing history of the user, which is a Privacy Considerations. (Unvalidated redirects and forwards)HTTP Referer header SHOULD NOT not sent by browsers if:
- the referring resource is a local "file" or "data" URI,
- an unsecured HTTP request is used and the referring page was received with a secure protocol (HTTPS).