APENFT market is built on a hybrid system (off-chain/on-chain), which incorporates off-chain signatures (these are called Maker Orders) and on-chain orders (called Taker Orders).
A maker order is a passive order, which can be executed (if not cancelled!) against a taker order after it is signed.
Parameters that are defined in a Solidity struct named Order described as below.

Order Struct

struct Order {
    address exchange;
    address maker;
    address taker;
    uint256 makerRelayerFee;
    uint256 takerRelayerFee;
    uint256 makerProtocolFee;
    uint256 takerProtocolFee;
    address feeRecipient;
    FeeMethod feeMethod;
    SaleKindInterface.Side side;
    SaleKindInterface.SaleKind saleKind;
    address target;
    HowToCall howToCall;
    bytes dataToCall;
    bytes replacementPattern;
    address staticTarget;
    bytes staticExtradata;
    address paymentToken;
    uint256 basePrice;
    uint256 extra;
    uint256 listingTime;
    uint256 expirationTime;
    uint256 salt;
}

Overview of parameters

exchange - APENFTExchange contract address
maker - wallet address used to make offer
taker - wallet address used to take offer
makerRelayerFee - royalty fee ratio for maker
takerRelayerFee - royalty fee ratio for taker
makerProtocolFee - APENFT service fee (paid by the seller to the platform)
takerProtocolFee - APENFT service fee (paid by the buyer to the platform)
feeMethod - fee method, set the value at 1
feeRecipient - Address for the royalty payment, designated by the project team (creator)
side - Buy/sell order identifier. Set the value at 0 for a buy order, and 1 for a sell order.
saleKind - Selling method, set the value at 0 (sell at a "fixed price")
target - NFT collection address
howToCall - how to call contract, set the value at 0
dataToCall - Encoded data of function name and parameters when making a transfer
replacementPattern - The replacement pattern for dataToCall
staticTarget - Set the extra parameter value as zero address for fixed-priced orders
staticExtradata - Extra parameter for an English auction, set the value as "0x"
paymentToken - Tokens used for order payment, set the value to token's contract address
basePrice - The listing price of order
extra - Extra auction parameter, set the value at 0
listingTime - Timestamp of listing
expirationTime - Timestamp of order expiration
salt - Order's salt，a string of random numbers with a length of 77 digits to prevent duplicate hash

Breakdown of parameters

exchange

APENFTExchange contract address
APENFTExchange contract address on mainnet：TQr5axvJzETeHsUiXv6QjBEh1BKH571AZu

maker

Seller's wallet address, in base58 format.

taker

Buyer's wallet address, in base58 format

makerRelayerFee

Author royalty (paid by the seller to the creator), maxium value is 50%

takerRelayerFee

Author royalty (paid by the buyer to the creator), maxium value is 50%

makerProtocolFee

APENFT service fee (paid by the seller to the platform)

takerProtocolFee

APENFT service fee (paid by the buyer to the platform)

feeMethod

Fee method, set the value at 1

feeRecipient

Address for the royalty payment, designated by the project team (creator)

side

Buy/sell order identifier. Set the value at 0 for a buy order, and 1 for a sell order.

saleKind

Selling method, set the value at 0 (sell at a "fixed price")

target

NFT collection address

howToCall

There are two types for call: 'call' and 'proxy call'. It is fixed value 0 (means 'call') for now.

dataToCall

Encoded data when making a transfer. Its structure as below:

function parseERC721DataToCall(
  bytes memory b
)internal pure
returns (
  bytes4 methodId,
  address to,
  uint256 tokenId
)

replacementPattern

When the sellOrder's replacementPattern is pattern one, the buyOrder's replacementPattern will be pattern two, and vice versa.

Pattern One: 0x000000000000000000000000000000000000000000000000000000000000000000000000ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff0000000000000000000000000000000000000000000000000000000000000000

Pattern Two: 0x00000000ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

staticTarget

Set the extra parameter value as zero-address： T9yD14Nj9j7xAB4dbGeiX9h8unkKHxuWwb for fixed-priced orders

staticExtradata

Extra parameter for an English auction, set the value as "0x"

paymentToken

Tokens used for order payment, zero-address： T9yD14Nj9j7xAB4dbGeiX9h8unkKHxuWwb for TRX

basePrice

The price of order, unit is wei, 100000000 = 100 TRX

extra

Extra auction parameter, set the value at 0

listingTime

Timestamp for listing time. Ten digits long, e.g., 1651040633.

expirationTime

Timestamp for order expiration. Ten digits long, e.g. 1651334400.

salt

A string of random numbers with a length of 77 digits, e.g., 76431802940535634443859288223886227759190472848754102518674791180720213667853; 0 cannot be used as the initial character