This function returns the url of the page or site the visitor came from

The information is sent by the users browser so do not rely on it always being there as users can switch it off

NOTE:
The mis-spelling of "referrer" as "referer" comes from the earliest days of the internet

Referrer url
<xt:referer />


Local urls only (no output for non local referrer)
<xt:referer local="y" />

Default location for no referrer or off site referrer when local is set to "y"
<xt:referer local="y" default="/index"/>
/index