MSH|^~\\&|SendingApp|SendingFac|ReceivingApp|ReceivingFac|20230823120000||ORU^R01|MessageControlID|P|2.5.1
The Message Header provide essential information about the message, its source, destination and other metadata. It is composed of 12 fields
MSH is the message header segment code.|^~\\& are delimiters used to separate fields, components, and subcomponents in the segment.SendingApp is the sending application's name or identifier.SendingFac is the sending facility's name or identifier.ReceivingApp is the receiving application's name or identifier.ReceivingFac is the receiving facility's name or identifier.20230823120000 is the message timestamp, in this case indicating August 23, 2023, at 12:00:00.Security in some applications of HL7, this field is used to implement security features. Its use is not yet further specified ; therefore we leave it emptyORU^R01 indicates the message type and trigger event.MessageControlID is a unique identifier for the message.P indicates that this is a production message.2.5.1.1 indicates the HL7 version being used.