---
type: "resource-definitions"
title: "Parameters Definitions"
resource: "Parameters"
---

# Parameters Definitions

<a id="Parameters"></a>

## Parameters
Operation Request or Response

**Definition:** This resource is used to pass information into and back from an operation (whether invoked directly from REST or within a messaging environment).  It is not persisted or allowed to be referenced by other resources.

**Comments:** The parameters that may be used are defined by the OperationDefinition resource.

**Cardinality:** 0..*

**Mappings:** v2=n/a; rim=n/a; w5=infrastructure.exchange


<a id="Parameters.parameter"></a>

## Parameters.parameter
Operation Parameter

**Definition:** A parameter passed to or received from the operation.

**Cardinality:** 0..*

**Type:** [BackboneElement](/BackboneElement)

**Summary:** true

**Constraints:** inv-1 | error | A parameter must have one and only one of (value, resource, part) | (part.exists() and value.empty() and resource.empty()) or (part.empty() and (value.exists() xor resource.exists()))


<a id="Parameters.parameter.name"></a>

## Parameters.parameter.name
Name from the definition

**Definition:** The name of the parameter (reference to the operation definition).

**Cardinality:** 1..1

**Type:** [string](/string)

**Summary:** true


<a id="Parameters.parameter.value[x]"></a>

## Parameters.parameter.value[x]
If parameter is a data type

**Definition:** Conveys the content if the parameter is a data type.

**Conditions:** inv-1

**Cardinality:** 0..1

**Type:** [base64Binary](/base64Binary), [boolean](/boolean), [canonical](/canonical), [code](/code), [date](/date), [dateTime](/dateTime), [decimal](/decimal), [id](/id), [instant](/instant), [integer](/integer), [integer64](/integer64), [markdown](/markdown), [oid](/oid), [positiveInt](/positiveInt), [string](/string), [time](/time), [unsignedInt](/unsignedInt), [uri](/uri), [url](/url), [uuid](/uuid), [Address](/Address), [Age](/Age), [Annotation](/Annotation), [Attachment](/Attachment), [CodeableConcept](/CodeableConcept), [Coding](/Coding), [ContactPoint](/ContactPoint), [Count](/Count), [Distance](/Distance), [Duration](/Duration), [HumanName](/HumanName), [Identifier](/Identifier), [Money](/Money), [Period](/Period), [Quantity](/Quantity), [Range](/Range), [Ratio](/Ratio), [Reference](/Reference), [SampledData](/SampledData), [Signature](/Signature), [Timing](/Timing), [ContactDetail](/ContactDetail), [DataRequirement](/DataRequirement), [Expression](/Expression), [ParameterDefinition](/ParameterDefinition), [RelatedArtifact](/RelatedArtifact), [TriggerDefinition](/TriggerDefinition), [UsageContext](/UsageContext), [Dosage](/Dosage), [CodeableReference](/CodeableReference), [Meta](/Meta)

**Summary:** true


<a id="Parameters.parameter.resource"></a>

## Parameters.parameter.resource
If parameter is a whole resource

**Definition:** Conveys the content if the parameter is a whole resource.

**Comments:** This may be a resource defined in the FHIR specification, or an [additional resource](resource.html#additional). When resolving references in resources, the operation definition may specify how references may be resolved between parameters. If a reference cannot be resolved between the parameters, the application should fall back to its general resource resolution methods.

**Conditions:** inv-1

**Cardinality:** 0..1

**Type:** [Resource](/Resource)

**Summary:** true


<a id="Parameters.parameter.part"></a>

## Parameters.parameter.part
Named part of a multi-part parameter

**Definition:** A named part of a multi-part parameter.

**Conditions:** inv-1

**Cardinality:** 0..*

**Summary:** true