{
  "id": "unmark-card",
  "description": "Remove a physical mark from a card",
  "labels": {
    "en": "Unmark card",
    "es": "Desmarcar carta",
    "fr": "Démarquer une carte",
    "de": "Markierung entfernen"
  },
  "action_contract": {
    "requires": [
      "target"
    ],
    "parameters": {
      "mark": {
        "required": false,
        "description": "The particular mark to remove; omitted means remove all marks",
        "domain": "string"
      }
    },
    "post_state_invariant": "The named mark is absent after the action; omitted mark leaves the target unmarked. No location, order or orientation change is implied."
  }
}