If you've downloaded a file, the system will guess in it's own way, and your viewers and editors will have their own settings. If, however, you meant how the s

If you've downloaded a file, the system will guess in it's own way, and your viewers and editors will have their own settings. If, however, you meant how the site is supposed to tell your browser how to interpret a file, it's in the Content-Type HTTP header. [0] In this case, setting something like: Content-Type: text/plain; charset=UTF-8 [0] https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Type https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Co...