[
  {
    "field": "report_id",
    "required": true,
    "reason": "Groups feedback by report."
  },
  {
    "field": "report_version",
    "required": true,
    "reason": "Prevents stale feedback from being applied to the wrong version."
  },
  {
    "field": "anchor_id",
    "required": true,
    "reason": "Points feedback to a precise block."
  },
  {
    "field": "feedback",
    "required": true,
    "reason": "Carries the user's actual comment."
  }
]