Defines the characteristics of a message that can be shared between systems, including the type of event that initiates the message, the content to be transmitted and what response(s), if any, are permitted.

MessageDefinition
url
Business Identifier for a given MessageDefinition
identifier
Primary key for the message definition on a given server
version
Business version of the message definition
name
Name for this message definition (computer friendly)
title
Name for this message definition (human friendly)
replaces
Takes the place of
status
draft | active | retired | unknown
experimental
For testing purposes, not real usage
date
Date last changed
publisher
Name of the publisher (organization or individual)
contact
Contact details for the publisher
description
Natural language description of the message definition
useContext
The context that the content is intended to support
jurisdiction
Intended jurisdiction for message definition (if applicable)
purpose
Why this message definition is defined
base
Definition this one is based on
parent
Protocol/workflow this is part of
event[x]
Event code or link to the EventDefinition
category
consequence | currency | notification
focus
Resource(s) that are the subject of the event
code
Type of resource
profile
Profile that must be adhered to by focus
min
Minimum number of focuses of this type
max
Maximum number of focuses of this type
responseRequired
always | on-error | never | on-success
allowedResponse
Responses to this message
message
Reference to allowed message definition response
situation
When should this response be used
graph
Canonical reference to a GraphDefinition