====== Standard Header ======

All messages (administrative or application) are preceded by a **Standard Header**.

The Standard Header provides:
  * Identification of FIX Session participants
  * Message Type (`Tag 35`)
  * Message Length (`Tag 9`)
  * Origination timestamps (`Tag 52`, `Tag 122`)
  * Message sequence order (`Tag 34`)
  * Additional details for:
    * Authentication
    * Resent or duplicate messages
    * Message routing and delivery

===== Standard Header Dictionary =====

^ Tag ^ Field Name ^ Req'd ^ Comments ^
| 8   | BeginString         | Y | FIX.4.2 |
| 9   | BodyLength          | Y | Length of Current Message |
| 35  | MsgType             | Y | Message Type |
| 49  | SenderCompID        | Y | T4 Firm Name (outbound from FIX API server). T4 Application Name (inbound into FIX API server). |
| 56  | TargetCompID        | Y | T4 Application Name (outbound from FIX API server). T4 Firm Name (inbound into FIX API server). |
| 90  | SecureDataLen       | N | Length of SecureData (Tag 91) field. Used only in Login Message. |
| 91  | SecureData          | N | T4 application license code. Used only in Login Message. |
| 34  | MsgSeqNum           | Y | Sequence number of current message |
| 50  | SenderSubID         | N | T4 User/Trader Name. Message originator. Conditionally required for non-administrative messages when in Multi-Trader mode. |
| 57  | TargetSubID         | N | T4 User/Trader Name. Message originator. |
| 43  | PossDupFlag         | N | "Y(es)" or "N(o)" - Indicates possible retransmission of message with this sequence number |
| 97  | PossResend          | N | "Y(es)" or "N(o)" - Indicates the message may duplicate one with another sequence number |
| 52  | SendingTime         | Y | UTC timestamp when the message is built in the CTS FIX API server |
| 122 | OrigSendingTime     | N | UTC timestamp of original message transmission for Resend Request messages |
| 369 | LastMsgSeqNumProcessed | N | Last received Sequence Number (Tag 34) by the T4 FIX API |