Entity_ItemEntity: {
    type: "compound";
    value: {
        Age: { type: "short"; value: number };
        Health: { type: "short"; value: number };
        Item: { type: "compound"; value: object } & Item_ItemStack;
        OwnerID: { type: "long"; value: [high: number, low: number] };
    };
} & ActorPrefix

Additional fields for item entity.