The MSH segment defines the intent, source, destination, and some specifics of the syntax of a message.

2.24.1.0 MSH field definitions

19
C.LenElementv2.2FHIR
1..1-STR1-00001MSH-1Field SeparatorName-
2..4-STR1-00002MSH-2Encoding CharactersName-
3..180-HDO1-00003MSH-3Sending Application44 mappings
4..180-HDO1-00004MSH-4Sending Facility45 mappings
5..180-HDO1-00005MSH-5Receiving Application43 mappings
6..180-HDO1-00006MSH-6Receiving Facility4destination[1].receiver(Organization)
7..26-TSO1-00007MSH-7Date / Time of MessageName3 mappings
8..40-STO1-00008MSH-8SecurityOptionalitymeta.security
9..7-CM_MSGR1-00009MSH-9Message Type23 mappings
10..20-STR1-00010MSH-10Message Control ID2 mappings
11..3-PTR1-00011MSH-11Processing ID3meta
12..8-IDR1010400012MSH-12Version ID-
13..15-NMO1-00013MSH-13Sequence Number2-
14..180-STO1-00014MSH-14Continuation Pointer2-
15..2-IDO1015500015MSH-15Accept Acknowledgement Type2-
16..2-IDO1015500016MSH-16Application Acknowledgement Type2-
17..2-IDO1-00017MSH-17Country Code2sender(Organization.address.country)
18..6-IDO1021100692MSH-18Character SetNEW-
19..3-CEO1-00693MSH-19Principal Language of MessageNEWlanguage
335