Optional
0 prefer non-forced, 1 prefer forced, 2 require forced, 3 require non-forced.
0 prefer non-SDH, 1 prefer SDH, 2 require SDH, 3 require non-SDH.
ISO 639-1 language code.
0 prefer non-forced, 1 prefer forced, 2 require forced, 3 require non-forced.