ajv/lib/refs/data.json

{
  "$id": "https://raw.githubusercontent.com/ajv-validator/ajv/master/lib/refs/data.json#",
  "description": "Meta-schema for $data reference (JSON AnySchema extension proposal)",
  "type": "object",
  "required": ["$data"],
  "properties": {
    "$data": {
      "type": "string",
      "anyOf": [{"format": "relative-json-pointer"}, {"format": "json-pointer"}]
    }
  },
  "additionalProperties": false
}