Structured tags Google attaches to some reviews in addition to the star rating, mostly on games. Array of objects with two keys: 'criteria' (the tag ID Google uses, e.g. 'vaf_app_quality_battery_efficiency') and 'rating' (a small integer level Google assigns for that tag - observed values are 1, 2 and 3, and Google does not publish what they mean, so treat it as an opaque code rather than a star score - or null when Google gives no level). Empty array for reviews with no tags.
Example:[object Object],[object Object]