  | 8 | BeginString |   | 
          FIX.4.2 (Always unencrypted, must be first field in message) 
       |   | 
  | 9 | BodyLength |   | 
          (Always unencrypted, must be second field in message) 
       |   | 
  | 35 | MsgType |   | 
          (Always unencrypted, must be third field in message) 
       |   | 
  | 49 | SenderCompID |   | 
          (Always unencrypted) 
       |   | 
  | 56 | TargetCompID |   | 
          (Always unencrypted) 
       |   | 
  | 115 | OnBehalfOfCompID |   | 
          Trading partner company ID used when sending messages via a third party (Can be embedded within encrypted data section.) 
       |   | 
  | 128 | DeliverToCompID |   | 
          Trading partner company ID used when sending messages via a third party (Can be embedded within encrypted data section.) 
       |   | 
  | 90 | SecureDataLen |   | 
          Required to identify length of encrypted section of message. (Always unencrypted) 
       |   | 
  | 91 | SecureData |   | 
          Required when message body is encrypted. Always immediately follows SecureDataLen field. 
       |   | 
  | 34 | MsgSeqNum |   | 
          (Can be embedded within encrypted data section.) 
       |   | 
  | 50 | SenderSubID |   | 
          (Can be embedded within encrypted data section.) 
       |   | 
  | 142 | SenderLocationID |   | 
          Sender's LocationID (i.e. geographic location and/or desk) (Can be embedded within encrypted data section.) 
       |   | 
  | 57 | TargetSubID |   | 
          "ADMIN" reserved for administrative messages not intended for a specific user. (Can be embedded within encrypted data section.) 
       |   | 
  | 143 | TargetLocationID |   | 
          Trading partner LocationID (i.e. geographic location and/or desk) (Can be embedded within encrypted data section.) 
       |   | 
  | 116 | OnBehalfOfSubID |   | 
          Trading partner SubID used when delivering messages via a third party. (Can be embedded within encrypted data section.) 
       |   | 
  | 144 | OnBehalfOfLocationID |   | 
          Trading partner LocationID (i.e. geographic location and/or desk) used when delivering messages via a third party. (Can be embedded within encrypted data section.) 
       |   | 
  | 129 | DeliverToSubID |   | 
          Trading partner SubID used when delivering messages via a third party. (Can be embedded within encrypted data section.) 
       |   | 
  | 145 | DeliverToLocationID |   | 
          Trading partner LocationID (i.e. geographic location and/or desk) used when delivering messages via a third party. (Can be embedded within encrypted data section.) 
       |   | 
  | 43 | PossDupFlag |   | 
          Always required for retransmitted messages, whether prompted by the sending system or as the result of a resend request. (Can be embedded within encrypted data section.) 
       |   | 
  | 97 | PossResend |   | 
          Required when message may be duplicate of another message sent under a different sequence number. (Can be embedded within encrypted data section.) 
       |   | 
  | 52 | SendingTime |   | 
          (Can be embedded within encrypted data section.) 
       |   | 
  | 122 | OrigSendingTime |   | 
          Required for message resent as a result of a ResendRequest. If data is not available set to same value as SendingTime (Can be embedded within encrypted data section.) 
       |   | 
  | 212 | XmlDataLen |   | 
          Required when specifying XmlData to identify the length of a XmlData message block. (Can be embedded within encrypted data section.) 
       |   | 
  | 213 | XmlData |   | 
          Can contain a XML formatted message block (e.g. FIXML). Always immediately follows XmlDataLen field. (Can be embedded within encrypted data section.) 
         See Appendix M – FIXML Support 
       |   | 
  | 347 | MessageEncoding |   | 
          Type of message encoding (non-ASCII characters) used in a message’s "Encoded" fields. Required if any "Encoding" fields are used. 
       |   | 
  | 369 | LastMsgSeqNumProcessed |   | 
          The last MsgSeqNum value received and processed. Can be specified on every message sent. Useful for detecting a backlog with a counterparty. 
       |   | 
  | 370 | OnBehalfOfSendingTime |   | 
          Used when a message is sent via a "hub" or "service bureau". If A sends to Q (the hub) who then sends to B via a separate FIX session, then when Q sends to B the value of this field should represent the SendingTime on the message A sent to Q. (always expressed in UTC (Universal Time Coordinated, also known as "GMT") 
       |   |