Item_FilledMap: {
    type: "compound";
    value: {
        tag?: {
            type: "compound";
            value: {
                map_display_players: { type: "byte"; value: number };
                map_is_init?: { type: "byte"; value: number };
                map_is_scaling?: { type: "byte"; value: number };
                map_name_index: { type: "int"; value: number };
                map_scale?: { type: "int"; value: number };
                map_uuid: { type: "long"; value: [high: number, low: number] };
            };
        };
    };
} & Item_ItemStack

Additional fields for [filled map](https://minecraft.wiki/w/filled map).