Q: iCloud Drive shows option for Reminders

I was doing something with the iCloud Drive settings and noticed that there's an option forReminders selected on both my iPhone and iPaD. This is separate from the Reminders option in the main iCloud settings. Any idea what the option's for? I know Safari and Mail can be used with iCloud Drive so that you can access it to attach/upload documents but haven't found a similar function in notes that would require access to the drive.