Question about abi decoding bytecode (params is a struct folded in another struct)

Smart Contracts
1

I didn't found any instructions about nested structs (in structs). Seen video about sending bytecode to contract and I wanted to understand.

For example, method is fulfillOrder:

function fulfillOrder(
    Order calldata order,
    bytes32 fulfillerConduitKey
) external payable returns (bool fulfilled);

struct Order {
    OrderParameters parameters;
    bytes signature;
}

struct OrderParameters {
    address offerer; // 0x00
    address zone; // 0x20
    OfferItem[] offer; // 0x40
    ConsiderationItem[] consideration; // 0x60
    OrderType orderType; // 0x80
    uint256 startTime; // 0xa0
    uint256 endTime; // 0xc0
    bytes32 zoneHash; // 0xe0
    uint256 salt; // 0x100
    bytes32 conduitKey; // 0x120
    uint256 totalOriginalConsiderationItems; // 0x140
    // offer.length                          // 0x160
}

struct OfferItem {
    ItemType itemType;
    address token;
    uint256 identifierOrCriteria;
    uint256 startAmount;
    uint256 endAmount;
}

struct ConsiderationItem {
    ItemType itemType;
    address token;
    uint256 identifierOrCriteria;
    uint256 startAmount;
    uint256 endAmount;
    address payable recipient;
}

enum OrderType {
    FULL_OPEN,
    PARTIAL_OPEN,
    FULL_RESTRICTED,
    PARTIAL_RESTRICTED,
    CONTRACT
}

abi calldata description:

fulfillOrder(((address,address,(uint8,address,uint256,uint256,uint256)[],(uint8,address,uint256,uint256,uint256,address)[],uint8,uint256,uint256,bytes32,uint256,bytes32,uint256),bytes),bytes32)

calldata abi keccak: b3a34c4c89989a0871b97285782de68e7db27f7d5fe738e7aa7c6f1f7118d3ac

I've google a lot, it's didn't gave any results...
That is my analysis, I tried to understand but I don't.

  0xb3a34c4c
  32/0000000000000000000000000000000000000000000000000000000000000040 .*args[0] 32*2       >-- Order
  64/0000007b02230091a7ed01230072f7006a004d60a8d4e71d599b8104250f0000 'fulfillerConduitKey   |
? 96/0000000000000000000000000000000000000000000000000000000000000040 'args[0] *Order[0]    <-    >--
? 128/0000000000000000000000000000000000000000000000000000000000000280'-------->32*20 link SIG      |  OrderParams
  160/000000000000000000000000047a0ba6eab7825a854049eda6256301cf0a7056' offerer Order[0] Start cnt <-
  192/0000000000000000000000000000000000000000000000000000000000000000' zone
? 224/0000000000000000000000000000000000000000000000000000000000000160'- *arr1 352 32*11 *OfferItem[]
? 256/0000000000000000000000000000000000000000000000000000000000000220'- 544 32*17
  288/0000000000000000000000000000000000000000000000000000000000000000'  orderType
  320/0000000000000000000000000000000000000000000000000000000000000000' FULL_OPEN OrderType - start static
  352/000000000000000000000000000000000000000000000000000000006383abd0' start time //1669573584
  384/0000000000000000000000000000000000000000000000000000000063ab38d0' end time //1672165584
  416/0000000000000000000000000000000000000000000000000000000000000000' zoneHash
  448/360c6ebe0000000000000000000000000000000000000000f69d6dec7287d948' salt
  480/0000007b02230091a7ed01230072f7006a004d60a8d4e71d599b8104250f0000' conduitKey
  512/000000000000000000000000b4fbf271143f4fbf7b91a5ded31805e42b2208d6'* arr1 weth
  544/0000000000000000000000000000000000000000000000000000000000000000'* identifierOrCriteria
  576/0000000000000000000000000000000000000000000000000de0b6b3a7640000'* start amount of weth 1*10^19
  608/0000000000000000000000000000000000000000000000000de0b6b3a7640000'* end amount
  640/0000000000000000000000000000000000000000000000000000000000000000' 20th
  672/0000000000000000000000000000000000000000000000000000000000000041 --- SIG length
  704/xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx ---
  736/xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx   } SIG value
  768/xx00000000000000000000000000000000000000000000000000000000000000 ---

Where first letter in string is question sign ?, I don't understood what is it means...
Maybe code is outdated? Where I can find out how struct in struct decoding to bytecode (calldata)?

2

The specification for calldata encoding can be found here:

https://docs.soliditylang.org/en/latest/abi-spec.html#abi

I haven't looked in detail at the specific calldata you shared. But see if the link helps.