{
  "display": {
    "icon": {
      "id": "minecraft:bundle",
      "components": {
        "minecraft:custom_model_data": {
          "strings": [
            "ndletter_22"
          ]
        }
      }
    },
    "title": {
      "translate": "urk.mail.advancement.box_recursive",
      "fallback": "12"
    },
    "description": {
      "translate": "urk.mail.advancement.box_recursive_desc",
      "fallback": "12"
    },
    "frame": "challenge"
  },
  "parent": "nd_urk_mail:urk_mail/urk_mail_seal_start",
  "criteria": {
    "trigger1": {
      "trigger": "minecraft:inventory_changed",
      "conditions": {
        "items": [
          {
            "items": [
              "minecraft:bundle"
            ],
            "components": {
              "minecraft:bundle_contents": [
                {
                  "id": "minecraft:bundle"
                }
              ]
            },
            "predicates": {
              "minecraft:custom_data": {
                "urk_mail_type": "postal_box"
              }
            }
          }
        ]
      }
    }
  }
}