WHO Digital Documentation of COVID-19 Certificates (DDCC)
1.0.0 - CI Build International flag

WHO Digital Documentation of COVID-19 Certificates (DDCC), published by WHO. This guide is not an authorized publication; it is the continuous build for version 1.0.0 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/WorldHealthOrganization/ddcc/tree/main and changes regularly. See the Directory of published versions

Logical Model: DDCC Core Data Set Logical Model ( Abstract )

Official URL: http://smart.who.int/ddcc/StructureDefinition/DDCCCoreDataSet Version: 1.0.0
Draft as of 2026-01-19 Computable Name: DDCCCoreDataSet

Data elements for the DDCC Core Data Set.

Usages:

You can also check for usages in the FHIR IG Statistics

Formal Views of Profile Content

Description of Profiles, Differentials, Snapshots and how the different presentations work.

NameFlagsCard.TypeDescription & Constraints    Filter: Filtersdoco
.. DDCCCoreDataSet 0..* Base This is an abstract type. Child types: DDCCCoreDataSetTR, DDCCCoreDataSetVS
DDCC Core Data Set Logical Model
... name Σ 1..1 string Name
... birthDate Σ 0..1 date Date of birth
... identifier Σ 0..1 Identifier Unique identifier
.... @id 0..1 string Unique id for inter-element referencing
.... extension 0..* Extension Additional content defined by implementations
Slice: Unordered, Open by value:url
.... modifierExtension ?!Σ 0..* Extension Extensions that cannot be ignored even if unrecognized
.... issuer Σ 1..1 Reference(DDCC Organization) Certificate issuer
.... kid 0..1 string Key ID used to verify the signature of the certificate
.... hcid Σ 1..1 Identifier Health certificate identifier (HCID)
.... ddccid Σ 0..1 Identifier DDCC Identifier
.... version Σ 1..1 string Certificate schema version
.... period C 0..1 Period Certificate Validity Period
Constraints: per-1
..... @id 0..1 string Unique id for inter-element referencing
..... extension 0..* Extension Additional content defined by implementations
Slice: Unordered, Open by value:url
..... start ΣC 0..1 dateTime Certificate valid from
..... end ΣC 0..1 dateTime Certificate valid until

doco Documentation for this format

Constraints

Id Grade Path(s) Description Expression
ele-1 error **ALL** elements All FHIR elements must have a @value or children hasValue() or (children().count() > id.count())
ext-1 error **ALL** extensions Must have either extensions or value[x], not both extension.exists() != value.exists()
per-1 error DDCCCoreDataSet.certificate.period If present, start SHALL have a lower value than end start.hasValue().not() or end.hasValue().not() or (start <= end)

This structure is derived from Base

NameFlagsCard.TypeDescription & Constraints    Filter: Filtersdoco
.. DDCCCoreDataSet 0..* Base This is an abstract type. Child types: DDCCCoreDataSetTR, DDCCCoreDataSetVS
DDCC Core Data Set Logical Model
... name Σ 1..1 string Name
... birthDate Σ 0..1 date Date of birth
... identifier Σ 0..1 Identifier Unique identifier
.... issuer Σ 1..1 Reference(DDCC Organization) Certificate issuer
.... kid 0..1 string Key ID used to verify the signature of the certificate
.... hcid Σ 1..1 Identifier Health certificate identifier (HCID)
.... ddccid Σ 0..1 Identifier DDCC Identifier
.... version Σ 1..1 string Certificate schema version
.... period 0..1 Period Certificate Validity Period
..... start 0..1 dateTime Certificate valid from
..... end 0..1 dateTime Certificate valid until

doco Documentation for this format
NameFlagsCard.TypeDescription & Constraints    Filter: Filtersdoco
.. DDCCCoreDataSet 0..* Base This is an abstract type. Child types: DDCCCoreDataSetTR, DDCCCoreDataSetVS
DDCC Core Data Set Logical Model
... name Σ 1..1 string Name
... birthDate Σ 0..1 date Date of birth
... identifier Σ 0..1 Identifier Unique identifier
.... @id 0..1 string Unique id for inter-element referencing
.... extension 0..* Extension Additional content defined by implementations
Slice: Unordered, Open by value:url
.... modifierExtension ?!Σ 0..* Extension Extensions that cannot be ignored even if unrecognized
.... issuer Σ 1..1 Reference(DDCC Organization) Certificate issuer
.... kid 0..1 string Key ID used to verify the signature of the certificate
.... hcid Σ 1..1 Identifier Health certificate identifier (HCID)
.... ddccid Σ 0..1 Identifier DDCC Identifier
.... version Σ 1..1 string Certificate schema version
.... period C 0..1 Period Certificate Validity Period
Constraints: per-1
..... @id 0..1 string Unique id for inter-element referencing
..... extension 0..* Extension Additional content defined by implementations
Slice: Unordered, Open by value:url
..... start ΣC 0..1 dateTime Certificate valid from
..... end ΣC 0..1 dateTime Certificate valid until

doco Documentation for this format

Constraints

Id Grade Path(s) Description Expression
ele-1 error **ALL** elements All FHIR elements must have a @value or children hasValue() or (children().count() > id.count())
ext-1 error **ALL** extensions Must have either extensions or value[x], not both extension.exists() != value.exists()
per-1 error DDCCCoreDataSet.certificate.period If present, start SHALL have a lower value than end start.hasValue().not() or end.hasValue().not() or (start <= end)

This structure is derived from Base

Summary

Mandatory: 0 element(4 nested mandatory elements)

Structures

This structure refers to these other structures:

Key Elements View

NameFlagsCard.TypeDescription & Constraints    Filter: Filtersdoco
.. DDCCCoreDataSet 0..* Base This is an abstract type. Child types: DDCCCoreDataSetTR, DDCCCoreDataSetVS
DDCC Core Data Set Logical Model
... name Σ 1..1 string Name
... birthDate Σ 0..1 date Date of birth
... identifier Σ 0..1 Identifier Unique identifier
.... @id 0..1 string Unique id for inter-element referencing
.... extension 0..* Extension Additional content defined by implementations
Slice: Unordered, Open by value:url
.... modifierExtension ?!Σ 0..* Extension Extensions that cannot be ignored even if unrecognized
.... issuer Σ 1..1 Reference(DDCC Organization) Certificate issuer
.... kid 0..1 string Key ID used to verify the signature of the certificate
.... hcid Σ 1..1 Identifier Health certificate identifier (HCID)
.... ddccid Σ 0..1 Identifier DDCC Identifier
.... version Σ 1..1 string Certificate schema version
.... period C 0..1 Period Certificate Validity Period
Constraints: per-1
..... @id 0..1 string Unique id for inter-element referencing
..... extension 0..* Extension Additional content defined by implementations
Slice: Unordered, Open by value:url
..... start ΣC 0..1 dateTime Certificate valid from
..... end ΣC 0..1 dateTime Certificate valid until

doco Documentation for this format

Constraints

Id Grade Path(s) Description Expression
ele-1 error **ALL** elements All FHIR elements must have a @value or children hasValue() or (children().count() > id.count())
ext-1 error **ALL** extensions Must have either extensions or value[x], not both extension.exists() != value.exists()
per-1 error DDCCCoreDataSet.certificate.period If present, start SHALL have a lower value than end start.hasValue().not() or end.hasValue().not() or (start <= end)

Differential View

This structure is derived from Base

NameFlagsCard.TypeDescription & Constraints    Filter: Filtersdoco
.. DDCCCoreDataSet 0..* Base This is an abstract type. Child types: DDCCCoreDataSetTR, DDCCCoreDataSetVS
DDCC Core Data Set Logical Model
... name Σ 1..1 string Name
... birthDate Σ 0..1 date Date of birth
... identifier Σ 0..1 Identifier Unique identifier
.... issuer Σ 1..1 Reference(DDCC Organization) Certificate issuer
.... kid 0..1 string Key ID used to verify the signature of the certificate
.... hcid Σ 1..1 Identifier Health certificate identifier (HCID)
.... ddccid Σ 0..1 Identifier DDCC Identifier
.... version Σ 1..1 string Certificate schema version
.... period 0..1 Period Certificate Validity Period
..... start 0..1 dateTime Certificate valid from
..... end 0..1 dateTime Certificate valid until

doco Documentation for this format

Snapshot View

NameFlagsCard.TypeDescription & Constraints    Filter: Filtersdoco
.. DDCCCoreDataSet 0..* Base This is an abstract type. Child types: DDCCCoreDataSetTR, DDCCCoreDataSetVS
DDCC Core Data Set Logical Model
... name Σ 1..1 string Name
... birthDate Σ 0..1 date Date of birth
... identifier Σ 0..1 Identifier Unique identifier
.... @id 0..1 string Unique id for inter-element referencing
.... extension 0..* Extension Additional content defined by implementations
Slice: Unordered, Open by value:url
.... modifierExtension ?!Σ 0..* Extension Extensions that cannot be ignored even if unrecognized
.... issuer Σ 1..1 Reference(DDCC Organization) Certificate issuer
.... kid 0..1 string Key ID used to verify the signature of the certificate
.... hcid Σ 1..1 Identifier Health certificate identifier (HCID)
.... ddccid Σ 0..1 Identifier DDCC Identifier
.... version Σ 1..1 string Certificate schema version
.... period C 0..1 Period Certificate Validity Period
Constraints: per-1
..... @id 0..1 string Unique id for inter-element referencing
..... extension 0..* Extension Additional content defined by implementations
Slice: Unordered, Open by value:url
..... start ΣC 0..1 dateTime Certificate valid from
..... end ΣC 0..1 dateTime Certificate valid until

doco Documentation for this format

Constraints

Id Grade Path(s) Description Expression
ele-1 error **ALL** elements All FHIR elements must have a @value or children hasValue() or (children().count() > id.count())
ext-1 error **ALL** extensions Must have either extensions or value[x], not both extension.exists() != value.exists()
per-1 error DDCCCoreDataSet.certificate.period If present, start SHALL have a lower value than end start.hasValue().not() or end.hasValue().not() or (start <= end)

This structure is derived from Base

Summary

Mandatory: 0 element(4 nested mandatory elements)

Structures

This structure refers to these other structures:

 

Other representations of profile: CSV, Excel