If you open the .ifo with ifoedit you can label an audio track with the correct language and also add an extension like "for visually impaired", "director's comment", "alternate director's comment". The subtitle track can be named with the correct language and a coding caption like "forced caption" or "director's comment". I don't think you can give the audio or subtitle tracks custom labels.
If you open the .ifo with ifoedit you can label an audio track with the correct language and also add an extension like "for visually impaired", "director's comment", "alternate director's comment". The subtitle track can be named with the correct language and a coding caption like "forced caption" or "director's comment". I don't think you can give the audio or subtitle tracks custom labels.