Best method: Access-Control-Allow-Origin Multiple Origin Domains
问题 This question has been asked on here before and given an array of good answers, mainly: Access-Control-Allow-Origin Multiple Origin Domains? However there seems to be a gap in explanation in terms of the approved method that should be undertaken. Reading through the W3 documentation we have what appears to me to be a conflict of guidance. Firstly we see the answer given as the right way to do it in a lot of the previous answers which dictates that the host server must dynamically echo back