I recently noticed that Font Book seems to have changed its database with respect to what it considers necessary for each language to show up as supported. For example, some of my fonts that were flagged as supporting Dutch and Turkish in older versions of Font Book (or Mac OS) are not showing these two any more.
Is there a way to access the language database in Font Book? Does anyone know which database they use? I tried to find out a few years ago, without success.
Even better, would it be possible to make this data accessible through Glyphs? That would be very handy. Although I wouldn’t consider Font Book the only authoritative source on this, it would be good to know which characters I need to include to make Font Book show a certain language as supported.