Standard Message Header 8 BeginString BeginString Y FIX.4.0 (Always unencrypted, must be first field in message) 9 BodyLength BodyLength Y (Always unencrypted, must be second field in message) 35 MsgType MsgType Y (Always unencrypted, must be third field in message) 49 SenderCompID SenderCompID Y (Always unencrypted) 56 TargetCompID TargetCompID Y (Always unencrypted) 115 OnBehalfOfCompID OnBehalfOfCompID N Trading partner company ID used when sending messages via a third party (Can be embedded within encrypted data section.) 128 DeliverToCompID DeliverToCompID N Trading partner company ID used when sending messages via a third party (Can be embedded within encrypted data section.) 90 SecureDataLen SecureDataLen N Required to identify length of encrypted section of message. (Always unencrypted) 91 SecureData SecureData N Required when message body is encrypted. Always immediately follows SecureDataLen field. 34 MsgSeqNum MsgSeqNum Y (Can be embedded within encrypted data section.) 50 SenderSubID SenderSubID N (Can be embedded within encrypted data section.) 57 TargetSubID TargetSubID N "ADMIN" reserved for administrative messages not intended for a specific user. (Can be embedded within encrypted data section.) 116 OnBehalfOfSubID OnBehalfOfSubID N Trading partner SubID used when delivering messages via a third party. (Can be embedded within encrypted data section.) 129 DeliverToSubID DeliverToSubID N Trading partner SubID used when delivering messages via a third party. (Can be embedded within encrypted data section.) 43 PossDupFlag PossDupFlag N Always required for retransmissions, whether prompted by the sending system or as the result of a resend request. (Can be embedded within encrypted data section.) 97 PossResend PossResend N Required when message may be duplicate of another message sent under a different sequence number. (Can be embedded within encrypted data section.) 52 SendingTime SendingTime Y (Can be embedded within encrypted data section.) 122 OrigSendingTime OrigSendingTime N Required for message resends. If data is not available set to same value as SendingTime (Can be embedded within encrypted data section.)