Added advanced subtitle/audio language filter to {MediaInfo ..}

Sonarr version (exact version):3.0.3.698
Mono version (if Sonarr is not running on Windows):
OS: Windows 10
Debug logs:
(Make sure debug logging is enabled in settings and post the full log to hastebin/pastebin/dropbox/google drive or something similar, do not post them directly here. Post in .txt not .doc, .rtf or some other formatted document)
Description of issue: Not really an issue

So what exactly does this mean in the changelog?

“Added advanced subtitle/audio language filter to {MediaInfo …}”

I want to set my profile to only download english subtitles/audio, how would i do this?

The update is only related to the {MediaInfo} token you can use in sonarr to rename your files. So basically after a download is complete, sonarr will parse the media info (codec, audio language, etc), and renames and moves it to your series folder.
Now you can filter which languages should be added to the file name.

Here is the pull request with more info https://github.com/Sonarr/Sonarr/pull/3484

Edit: as for your question: sonarr can only guess the language of a download based on the name. As long as your tracker has decently named releases this shouldn’t be much of an issue. If there is no language present in the release name, sonarr assumes it’s English audio. Subtitles are impossible, no release name has that information.