| Package | hl7.v2plus |
| Resource Type | StructureDefinition |
| Id | EI |
| FHIR Version | R5 |
| Source | http://somewhere.org/fhir/uv/v2plus/https://build.fhir.org/ig/HL7/v2ig/StructureDefinition-EI.html |
| URL | http://hl7.org/v2/StructureDefinition/EI |
| Version | 0.0.0 |
| Status | active |
| Date | 2025-07-11T16:45:01+00:00 |
| Name | EI |
| Title | HL7 v2 EI Data Type |
| Authority | hl7 |
| Description | The EI is appropriate for, but not limited to, machine or software generated identifiers. The generated identifier goes in the first component. The remaining components, 2 through 4, are known as the assigning authority; they identify the machine/system responsible for generating the identifier in component 1. The specified series, the assigning authority, is defined by components 2 through 4. The assigning authority is of the hierarchic designator (HD) data type, but it is defined as three separate components in the EI data type, rather than as a single component as would normally be the case. This is in order to maintain backward compatibility with the EI’s use as a component in several existing data fields. Otherwise, the components 2 through 4 are as defined in Section _2A.2.33_, "_HD - hierarchic designator_". Hierarchic designators (HD) are unique across a given HL7 implementation. |
| Type | http://hl7.org/v2/StructureDefinition/EI |
| Kind | logical |
| StructureDefinition | |
| EIP | HL7 v2 EIP Data Type |
| PIP | HL7 v2 PIP Data Type |
| PL | HL7 v2 PL Data Type |
| XAD | HL7 v2 XAD Data Type |
| XTN | HL7 v2 XTN Data Type |
| StructureDefinition | |
| ID | HL7 v2 ID Data Type |
| IS | HL7 v2 IS Data Type |
| ST | HL7 v2 String Primitive Type |
| complex-data-type | HL7 v2 Complex Data Type |
| ValueSet | |
| v2-0301 | hl7VS-universalIdType |
Note: links and images are rebased to the (stated) source
Generated Narrative: StructureDefinition EI
Profile: HL7 v2 Complex Data Type Profile
| Name | Flags | Card. | Type | Description & Constraints |
|---|---|---|---|---|
  EI | 0..* | V2ComplexDataType | entity identifier | |
  1 | 0..1 | string | Entity Identifier | |
| 2 | 0..1 | code | Namespace ID Binding: http://terminology.hl7.org/ValueSet/v2-0363 (required) | |
| 3 | 0..1 | string | Universal ID | |
 4 | 0..1 | code | Universal ID Type Binding: hl7VS-universalIdType (required) | |
| Documentation for this format | ||||
FHIR{
"resourceType": "StructureDefinition",
"id": "EI",
"meta": {
"profile": [
"http://hl7.org/v2/StructureDefinition/complex-data-type-profile"
]
},
"text": {
"status": "extensions",
"div": "<!-- snip (see above) -->"
},
"extension": [
{
"url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status",
"valueCode": "informative",
"_valueCode": {
"extension": [
{
"url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-conformance-derivedFrom",
"valueCanonical": "http://somewhere.org/fhir/uv/v2plus/ImplementationGuide/hl7.other.uv.v2plus"
}
]
}
}
],
"url": "http://hl7.org/v2/StructureDefinition/EI",
"version": "0.0.0",
"name": "EI",
"title": "HL7 v2 EI Data Type",
"status": "active",
"date": "2025-07-11T16:45:01+00:00",
"publisher": "HL7 International",
"contact": [
{
"telecom": [
{
"system": "url",
"value": "http://hl7.org/Special/committees/v2mgmt"
}
]
}
],
"description": "The EI is appropriate for, but not limited to, machine or software generated identifiers. The generated identifier goes in the first component. The remaining components, 2 through 4, are known as the assigning authority; they identify the machine/system responsible for generating the identifier in component 1.\n\nThe specified series, the assigning authority, is defined by components 2 through 4. The assigning authority is of the hierarchic designator (HD) data type, but it is defined as three separate components in the EI data type, rather than as a single component as would normally be the case. This is in order to maintain backward compatibility with the EI’s use as a component in several existing data fields. Otherwise, the components 2 through 4 are as defined in Section _2A.2.33_, \"_HD - hierarchic designator_\". Hierarchic designators (HD) are unique across a given HL7 implementation.",
"fhirVersion": "5.0.0",
"mapping": [
{
"identity": "rim",
"uri": "http://hl7.org/v3",
"name": "RIM Mapping"
}
],
"kind": "logical",
"abstract": false,
"type": "http://hl7.org/v2/StructureDefinition/EI",
"baseDefinition": "http://hl7.org/v2/StructureDefinition/complex-data-type",
"derivation": "specialization",
"snapshot": {
"extension": [
{
"url": "http://hl7.org/fhir/tools/StructureDefinition/snapshot-base-version",
"valueString": "0.0.0"
}
],
"element": [
{
"id": "EI",
"path": "EI",
"short": "entity identifier",
"definition": "*Definition:* The entity identifier defines a given entity within a specified series of identifiers.",
"min": 0,
"max": "*",
"base": {
"path": "Base",
"min": 0,
"max": "*"
},
"isModifier": false,
"mapping": [
{
"identity": "rim",
"map": "n/a"
}
]
},
{
"id": "EI.1",
"extension": [
{
"url": "http://hl7.org/v2/StructureDefinition/optionality",
"valueCode": "O"
},
{
"extension": [
{
"url": "length",
"valueInteger": 199
},
{
"url": "noTruncate",
"valueBoolean": true
}
],
"url": "http://hl7.org/v2/StructureDefinition/conformance-length"
}
],
"path": "EI.1",
"short": "Entity Identifier",
"min": 0,
"max": "1",
"base": {
"path": "EI.1",
"min": 0,
"max": "1"
},
"type": [
{
"code": "http://hl7.org/v2/StructureDefinition/ST"
}
]
},
{
"id": "EI.2",
"extension": [
{
"url": "http://hl7.org/v2/StructureDefinition/optionality",
"valueCode": "O"
},
{
"extension": [
{
"url": "length",
"valueInteger": 20
},
{
"url": "noTruncate",
"valueBoolean": true
}
],
"url": "http://hl7.org/v2/StructureDefinition/conformance-length"
}
],
"path": "EI.2",
"short": "Namespace ID",
"min": 0,
"max": "1",
"base": {
"path": "EI.2",
"min": 0,
"max": "1"
},
"type": [
{
"code": "http://hl7.org/v2/StructureDefinition/IS"
}
],
"binding": {
"strength": "required",
"valueSet": "http://terminology.hl7.org/ValueSet/v2-0363"
}
},
{
"id": "EI.3",
"extension": [
{
"url": "http://hl7.org/v2/StructureDefinition/optionality",
"valueCode": "C"
},
{
"extension": [
{
"url": "length",
"valueInteger": 199
},
{
"url": "noTruncate",
"valueBoolean": true
}
],
"url": "http://hl7.org/v2/StructureDefinition/conformance-length"
}
],
"path": "EI.3",
"short": "Universal ID",
"min": 0,
"max": "1",
"base": {
"path": "EI.3",
"min": 0,
"max": "1"
},
"type": [
{
"code": "http://hl7.org/v2/StructureDefinition/ST"
}
]
},
{
"id": "EI.4",
"extension": [
{
"url": "http://hl7.org/v2/StructureDefinition/optionality",
"valueCode": "C"
},
{
"extension": [
{
"url": "min",
"valueInteger": 1
},
{
"url": "max",
"valueInteger": 6
}
],
"url": "http://hl7.org/v2/StructureDefinition/length"
}
],
"path": "EI.4",
"short": "Universal ID Type",
"min": 0,
"max": "1",
"base": {
"path": "EI.4",
"min": 0,
"max": "1"
},
"type": [
{
"code": "http://hl7.org/v2/StructureDefinition/ID"
}
],
"binding": {
"strength": "required",
"valueSet": "http://terminology.hl7.org/ValueSet/v2-0301"
}
}
]
},
"differential": {
"element": [
{
"id": "EI",
"path": "EI",
"short": "entity identifier",
"definition": "*Definition:* The entity identifier defines a given entity within a specified series of identifiers.",
"min": 0,
"max": "*"
},
{
"id": "EI.1",
"extension": [
{
"url": "http://hl7.org/v2/StructureDefinition/optionality",
"valueCode": "O"
},
{
"extension": [
{
"url": "length",
"valueInteger": 199
},
{
"url": "noTruncate",
"valueBoolean": true
}
],
"url": "http://hl7.org/v2/StructureDefinition/conformance-length"
}
],
"path": "EI.1",
"short": "Entity Identifier",
"min": 0,
"max": "1",
"type": [
{
"code": "http://hl7.org/v2/StructureDefinition/ST"
}
]
},
{
"id": "EI.2",
"extension": [
{
"url": "http://hl7.org/v2/StructureDefinition/optionality",
"valueCode": "O"
},
{
"extension": [
{
"url": "length",
"valueInteger": 20
},
{
"url": "noTruncate",
"valueBoolean": true
}
],
"url": "http://hl7.org/v2/StructureDefinition/conformance-length"
}
],
"path": "EI.2",
"short": "Namespace ID",
"min": 0,
"max": "1",
"type": [
{
"code": "http://hl7.org/v2/StructureDefinition/IS"
}
],
"binding": {
"strength": "required",
"valueSet": "http://terminology.hl7.org/ValueSet/v2-0363"
}
},
{
"id": "EI.3",
"extension": [
{
"url": "http://hl7.org/v2/StructureDefinition/optionality",
"valueCode": "C"
},
{
"extension": [
{
"url": "length",
"valueInteger": 199
},
{
"url": "noTruncate",
"valueBoolean": true
}
],
"url": "http://hl7.org/v2/StructureDefinition/conformance-length"
}
],
"path": "EI.3",
"short": "Universal ID",
"min": 0,
"max": "1",
"type": [
{
"code": "http://hl7.org/v2/StructureDefinition/ST"
}
]
},
{
"id": "EI.4",
"extension": [
{
"url": "http://hl7.org/v2/StructureDefinition/optionality",
"valueCode": "C"
},
{
"extension": [
{
"url": "min",
"valueInteger": 1
},
{
"url": "max",
"valueInteger": 6
}
],
"url": "http://hl7.org/v2/StructureDefinition/length"
}
],
"path": "EI.4",
"short": "Universal ID Type",
"min": 0,
"max": "1",
"type": [
{
"code": "http://hl7.org/v2/StructureDefinition/ID"
}
],
"binding": {
"strength": "required",
"valueSet": "http://terminology.hl7.org/ValueSet/v2-0301"
}
}
]
}
}