The Content-Disposition response-header field has been proposed as a means for the origin server to suggest a default filename if the user requests that the content is saved to a file.
Example:
Content-Disposition: attachment; filename="fname.csv"
Note: In the context of a CORS request, use the Access-Control-Expose-Headers Http header to expose Content-Disposition as a header value.
Access-Control-Expose-Headers
Content-Disposition
References:
https://www.w3.org/Protocols/rfc2616/rfc2616-sec19.html