Access-Control-Request-Headers request header is used by browsers when issuing a preflight request, to let the server know which HTTP headers the client might send when the actual request is made (such as with
setRequestHeader()). This browser side header will be answered by the complementary server side header of
Access-Control-Request-Headers: <header-name>, <header-name>, ...
- A comma-delimited list of HTTP headers that are included in the request.
Access-Control-Request-Headers: X-PINGOTHER, Content-Type