ItemMessageHeader

 <DataSender>
   <Identifyer Type=GLN 8719328024200
 <DataReceiver
   <Identifyer Type=GLN 8719328024200
 <MessageIdentifier>a1a1140b-1859-4fe5-b4f4-0cd843f9e1c3
 <Creation DateTime 2021-12-17 11:26:25.578441510 +0530

</ItemHeader>

ItemMessageHeader is mandotary for every message

Parties {one or more parties, with ID and name}
- PartyType {Datasender, Datarecipient, Informationprovider}
- PartyIdentifierType {GLN, DataSenderPartyIDs, DataReceiverPartyIDs}
- PartyName