The origin value for SVG specifies only the ASCII serialization of the request’s referrerURL is sent as referrer information when making both same-origin-referrer requests and cross-origin-referrer requests.

origin

• empty-string
• no-referrer
• no-referrer-when-downgrade
• origin-when-cross-origin
• same-origin
• strict-origin
• strict-origin-when-cross-origin
• unsafe-url

• World Wide Web Consortium (W3C)