A single order message could comprise an Order Header Message (ORDHDR), multiple Orders Messages (
ORDERS), Order Trailer Message (
ORDTLR). Multiple individual order message can repeat between the
ORDHDR and the
ORDTLR.
A TRADACOMS file consists of a series of messages. Each message has a similar overall structure, beginning with a Message Header Segment (MHD) and ending with a Message Trailer Segment (
MTR). The contents, however, are different for each transaction type or File Format (for example, Orders, Invoices).