The Http Cross-Origin-Opener-Policy (COOP) response header allows a website to control whether a new top-level document, opened using Window.open() or by navigating to a new page, is opened in the same browsing context group (BCG) or in a new browsing context group....Remember language Deutsch 日本語 The HTTP Cross-Origin-Opener-Policy (COOP)...Forbidden header name No Syntax http Cross-Origin-Opener-Policy:...