This function is EXPERIMENTAL. The behaviour of this function, the name of this function, and anything else documented about this function may change in a future release of PHP without notice. Be warned and use this function at your own risk.
If encoding is set, mb_http_output() sets HTTP output character encoding to encoding. Output after this function is converted to encoding. mb_http_output() returns TRUE for success and FALSE for failure.
If encoding is omitted, mb_http_output() returns current HTTP output character encoding.