Sec,fetch,site:,cross,site -

— Indicates the "what" (data fetch, not an image or script).

— Indicates the "where" (different domain). sec,fetch,site:,cross,site

— Indicates the "how" (using the Fetch API/CORS). — Indicates the "what" (data fetch, not an

: A user on site-a.com clicks a button that sends a POST to site-b.com . — Indicates the "what" (data fetch