When enabled, this behavior strictly allows requests only from the allowed list of domains that you specify.

Features and options

Field	What it does
Enable	When On, only requests with a matching `Referer` header are allowed. When Off, all requests are allowed.
Strict Referrer Checking	When Strict Referrer Checking is enabled, requests whose `Referer` cannot be used to determine a hostname (i.e., relative path `Referer` such as `/mypath/index.html`) and requests without a `Referer` header are denied. When disabled, only `Referer` headers that contain a hostname that doesn't match the list of allowed domains are denied.
Domain	Specifies the set of allowed domains. You can create an allowed domain list as a space separated list of domains. For example, `example1.com example2.com example3.com` With Include Child Domains disabled, prefixing values with `.` specifies domains for which subdomains are allowed (e.g., `.example1.com`).
Include Child Domains	When enabled, allows all subdomains for the domains set, just like adding a `*.` prefix to each.