---
type: "search-params"
title: "MessageHeader Search Parameters"
resource: "MessageHeader"
---
# MessageHeader Search Parameters

<a id="code"></a>

## code
**Description:** ok | transient-error | fatal-error

**Type:** token

**Expression:** MessageHeader.response.code

**Path:** MessageHeader.response.code

**Standards Status:** normative

**URL:** http://hl7.org/fhir/build/SearchParameter/MessageHeader-code


<a id="destination"></a>

## destination
**Description:** Name of system

**Type:** string

**Expression:** MessageHeader.destination.name

**Path:** MessageHeader.destination.name

**Standards Status:** normative

**URL:** http://hl7.org/fhir/build/SearchParameter/MessageHeader-destination


<a id="event"></a>

## event
**Description:** Code for the event this message represents or link to event definition

**Type:** token

**Expression:** MessageHeader.event.ofType(Coding) | MessageHeader.event.ofType(canonical)

**Path:** MessageHeader.event[x]

**Standards Status:** normative

**URL:** http://hl7.org/fhir/build/SearchParameter/MessageHeader-event


<a id="focus"></a>

## focus
**Description:** The actual content of the message

**Type:** reference

**Expression:** MessageHeader.focus

**Path:** MessageHeader.focus

**Standards Status:** normative

**URL:** http://hl7.org/fhir/build/SearchParameter/MessageHeader-focus


<a id="receiver"></a>

## receiver
**Description:** Intended "real-world" recipient for the data

**Type:** reference

**Expression:** MessageHeader.destination.receiver

**Path:** MessageHeader.destination.receiver

**Standards Status:** normative

**URL:** http://hl7.org/fhir/build/SearchParameter/MessageHeader-receiver


<a id="response-id"></a>

## response-id
**Description:** Id of original message

**Type:** token

**Expression:** MessageHeader.response.identifier

**Path:** MessageHeader.response.identifier

**Standards Status:** normative

**URL:** http://hl7.org/fhir/build/SearchParameter/MessageHeader-response-id


<a id="sender"></a>

## sender
**Description:** Real world sender of the message

**Type:** reference

**Expression:** MessageHeader.source.sender

**Path:** MessageHeader.source.sender

**Standards Status:** normative

**URL:** http://hl7.org/fhir/build/SearchParameter/MessageHeader-sender


<a id="source"></a>

## source
**Description:** Name of system

**Type:** string

**Expression:** MessageHeader.source.name

**Path:** MessageHeader.source.name

**Standards Status:** normative

**URL:** http://hl7.org/fhir/build/SearchParameter/MessageHeader-source