Those rules[1] specify whether or not a cross-origin request is considered "simple". If the request is not cross-origin, you can basically do whatever you want.

Those rules[1] specify whether or not a cross-origin request is considered "simple". If the request is not cross-origin, you can basically do whatever you want. [1]: https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS#simple_requests https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS#simpl...