Demographics and administrative information about a person independent of a specific health-related context.

The Person resource does justice to person registries that keep track of persons regardless of their role. The Person resource is also a primary resource to point to for people acting in a particular role such as SubjectofCare, Practitioner, and Agent. Very few attributes are specific to any role and so Person is kept lean. Most attributes are expected to be tied to the role the Person plays rather than the Person himself. Examples of that are Guardian (SubjectofCare), ContactParty (SubjectOfCare, Practitioner), and multipleBirthInd (SubjectofCare).

A reference to a set of rules that were followed when the resource was constructed, and which must be understood when processing the content.

Asserting this rule set restricts the content to be only understood by a limited set of trading partners. This inherently limits the usefulness of the data in the long term. However, the existing health eco-system is highly fractured, and not yet ready to define, collect, and exchange data in a generally computable sense. Wherever possible, implementers and/or specification writers should avoid using this element.

This element is labelled as a modifier because the implicit rules may provide additional knowledge about the resource that modifies it's meaning or interpretation.

May be used to represent additional information that is not part of the basic definition of the resource, and that modifies the understanding of the element that contains it. Usually modifier elements provide negation or qualification. In order to make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

Whether this person's record is in active use.

Need to be able to mark a person record as not to be used because it was created in error.

R4B: Person.meta additional types (Meta) additional types from child elements (lastUpdated, profile, security, source, tag, versionId)

Element Person.meta is mapped to FHIR STU3 element Person.meta as SourceIsBroaderThanTarget. The mappings for Person.meta do not cover the following types: Meta. The mappings for Person.meta do not cover the following types based on type expansion: lastUpdated, profile, security, source, tag, versionId.

R4B: Person.text additional types (Narrative) additional types from child elements (div, status)

Element Person.text is mapped to FHIR STU3 element Person.text as SourceIsBroaderThanTarget. The mappings for Person.text do not cover the following types: Narrative. The mappings for Person.text do not cover the following types based on type expansion: div, status. Contained resources do not have narrative. Resources that are not contained SHOULD have a narrative. In some cases, a resource may only have text with little or no additional discrete data (as long as all minOccurs=1 elements are satisfied). This may be necessary for data from legacy systems where information is captured as a "text blob" or where text is additionally entered raw or narrated and encoded information is added later.

R4B: Person.identifier additional types (Identifier) additional types from child elements (assigner, period, system, type, use, value)

Element Person.identifier is mapped to FHIR STU3 element Person.identifier as SourceIsBroaderThanTarget. The mappings for Person.identifier do not cover the following types: Identifier. The mappings for Person.identifier do not cover the following types based on type expansion: assigner, period, system, type, use, value.

R4B: Person.name additional types (HumanName) additional types from child elements (family, given, period, prefix, suffix, text, use)

Element Person.name is mapped to FHIR STU3 element Person.name as SourceIsBroaderThanTarget. The mappings for Person.name do not cover the following types: HumanName. The mappings for Person.name do not cover the following types based on type expansion: family, given, period, prefix, suffix, text, use. Person may have multiple names with different uses or applicable periods.

R4B: Person.telecom additional types (ContactPoint) additional types from child elements (period, rank, system, use, value)

Element Person.telecom is mapped to FHIR STU3 element Person.telecom as SourceIsBroaderThanTarget. The mappings for Person.telecom do not cover the following types: ContactPoint. The mappings for Person.telecom do not cover the following types based on type expansion: period, rank, system, use, value. Person may have multiple ways to be contacted with different uses or applicable periods. May need to have options for contacting the person urgently and also to help with identification.

R4B: Person.address additional types (Address) additional types from child elements (city, country, district, line, period, postalCode, state, text, type, use)

Element Person.address is mapped to FHIR STU3 element Person.address as SourceIsBroaderThanTarget. The mappings for Person.address do not cover the following types: Address. The mappings for Person.address do not cover the following types based on type expansion: city, country, district, line, period, postalCode, state, text, type, use. Person may have multiple addresses with different uses or applicable periods.

R4B: Person.photo additional types (Attachment) additional types from child elements (contentType, creation, data, hash, language, size, title, url)

Element Person.photo is mapped to FHIR STU3 element Person.photo as SourceIsBroaderThanTarget. The mappings for Person.photo do not cover the following types: Attachment. The mappings for Person.photo do not cover the following types based on type expansion: contentType, creation, data, hash, language, size, title, url.

R4B: Person.managingOrganization additional types from child elements (display, identifier, reference, type)

Element Person.managingOrganization is mapped to FHIR STU3 element Person.managingOrganization as SourceIsBroaderThanTarget. The mappings for Person.managingOrganization do not cover the following types based on type expansion: display, identifier, reference, type. The standard extension alternate-reference has been mapped as the representation of FHIR R4B element Person.managingOrganization with unmapped reference targets: Organization.

R4B: Person.link.target

Element Person.link.target is mapped to FHIR STU3 element Person.link.target as SourceIsBroaderThanTarget. The standard extension alternate-reference has been mapped as the representation of FHIR R4B element Person.link.target with unmapped reference targets: Patient, Person, Practitioner, RelatedPerson.

Demographics and administrative information about a person independent of a specific health-related context.

The Person resource does justice to person registries that keep track of persons regardless of their role. The Person resource is also a primary resource to point to for people acting in a particular role such as SubjectofCare, Practitioner, and Agent. Very few attributes are specific to any role and so Person is kept lean. Most attributes are expected to be tied to the role the Person plays rather than the Person himself. Examples of that are Guardian (SubjectofCare), ContactParty (SubjectOfCare, Practitioner), and multipleBirthInd (SubjectofCare).

The logical id of the resource, as used in the URL for the resource. Once assigned, this value never changes.

The only time that a resource does not have an id is when it is being submitted to the server using a create operation.

The metadata about the resource. This is content that is maintained by the infrastructure. Changes to the content may not always be associated with version changes to the resource.

unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

An Extension

R4B: Person.meta additional types (Meta) additional types from child elements (lastUpdated, profile, security, source, tag, versionId)

Element Person.meta is mapped to FHIR STU3 element Person.meta as SourceIsBroaderThanTarget. The mappings for Person.meta do not cover the following types: Meta. The mappings for Person.meta do not cover the following types based on type expansion: lastUpdated, profile, security, source, tag, versionId.

The version specific identifier, as it appears in the version portion of the URL. This values changes when the resource is created, updated, or deleted.

The server assigns this value, and ignores what the client specifies, except in the case that the server is imposing version integrity on updates/deletes.

When the resource last changed - e.g. when the version changed.

This value is always populated except when the resource is first being created. The server / resource manager sets this value; what a client provides is irrelevant.

A list of profiles (references to StructureDefinition resources) that this resource claims to conform to. The URL is a reference to StructureDefinition.url.

It is up to the server and/or other infrastructure of policy to determine whether/how these claims are verified and/or updated over time. The list of profile URLs is a set.

Security labels applied to this resource. These tags connect specific resources to the overall security policy and infrastructure.

The security labels can be updated without changing the stated version of the resource The list of security labels is a set. Uniqueness is based the system/code, and version and display are ignored.

Security Labels from the Healthcare Privacy and Security Classification System.

Tags applied to this resource. Tags are intended to be used to identify and relate resources to process and workflow, and applications are not required to consider the tags when interpreting the meaning of a resource.

The tags can be updated without changing the stated version of the resource. The list of tags is a set. Uniqueness is based the system/code, and version and display are ignored.

Codes that represent various types of tags, commonly workflow-related; e.g. "Needs review by Dr. Jones"

A reference to a set of rules that were followed when the resource was constructed, and which must be understood when processing the content.

Asserting this rule set restricts the content to be only understood by a limited set of trading partners. This inherently limits the usefulness of the data in the long term. However, the existing health eco-system is highly fractured, and not yet ready to define, collect, and exchange data in a generally computable sense. Wherever possible, implementers and/or specification writers should avoid using this element.

This element is labelled as a modifier because the implicit rules may provide additional knowledge about the resource that modifies it's meaning or interpretation.

The base language in which the resource is written.

Language is provided to support indexing and accessibility (typically, services such as text to speech use the language tag). The html language tag in the narrative applies to the narrative. The language tag on the resource may be used to specify the language of other presentations generated from the data in the resource Not all the content has to be in the base language. The Resource.language should not be assumed to apply to the narrative automatically. If a language is specified, it should it also be specified on the div element in the html (see rules in HTML5 for information about the relationship between xml:lang and the html lang attribute).

A human language.

A human-readable narrative that contains a summary of the resource, and may be used to represent the content of the resource to a human. The narrative need not encode all the structured data, but is required to contain sufficient detail to make it "clinically safe" for a human to just read the narrative. Resource definitions may define what content should be represented in the narrative to ensure clinical safety.

Contained resources do not have narrative. Resources that are not contained SHOULD have a narrative. In some cases, a resource may only have text with little or no additional discrete data (as long as all minOccurs=1 elements are satisfied). This may be necessary for data from legacy systems where information is captured as a "text blob" or where text is additionally entered raw or narrated and encoded in formation is added later.

unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

An Extension

R4B: Person.text additional types (Narrative) additional types from child elements (div, status)

Element Person.text is mapped to FHIR STU3 element Person.text as SourceIsBroaderThanTarget. The mappings for Person.text do not cover the following types: Narrative. The mappings for Person.text do not cover the following types based on type expansion: div, status. Contained resources do not have narrative. Resources that are not contained SHOULD have a narrative. In some cases, a resource may only have text with little or no additional discrete data (as long as all minOccurs=1 elements are satisfied). This may be necessary for data from legacy systems where information is captured as a "text blob" or where text is additionally entered raw or narrated and encoded information is added later.

The status of the narrative - whether it's entirely generated (from just the defined data or the extensions too), or whether a human authored it and it may contain additional data.

The status of a resource narrative

The actual narrative content, a stripped down version of XHTML.

The contents of the html element are an XHTML fragment containing only the basic html formatting elements described in chapters 7-11 and 15 of the HTML 4.0 standard, <a> elements (either name or href), images and internally contained stylesheets. The XHTML content may not contain a head, a body, external stylesheet references, scripts, forms, base/link/xlink, frames, iframes and objects.

These resources do not have an independent existence apart from the resource that contains them - they cannot be identified independently, and nor can they have their own independent transaction scope.

This should never be done when the content can be identified properly, as once identification is lost, it is extremely difficult (and context dependent) to restore it again.

May be used to represent additional information that is not part of the basic definition of the resource. In order to make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

May be used to represent additional information that is not part of the basic definition of the resource, and that modifies the understanding of the element that contains it. Usually modifier elements provide negation or qualification. In order to make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

Identifier for a person within a particular scope.

People are known by a variety of ids. Some institutions maintain several, and most collect identifiers for exchange with other organizations concerning the person. Examples are national person identifier and local identifier.

unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

An Extension

R4B: Person.identifier additional types (Identifier) additional types from child elements (assigner, period, system, type, use, value)

Element Person.identifier is mapped to FHIR STU3 element Person.identifier as SourceIsBroaderThanTarget. The mappings for Person.identifier do not cover the following types: Identifier. The mappings for Person.identifier do not cover the following types based on type expansion: assigner, period, system, type, use, value.

The purpose of this identifier.

This is labeled as "Is Modifier" because applications should not mistake a temporary id for a permanent one. Applications can assume that an identifier is permanent unless it explicitly says that it is temporary.

Identifies the purpose for this identifier, if known .

Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers.

A coded type for the identifier that can be used to determine which identifier to use for a specific purpose.

This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage.

Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type.

A coded type for an identifier that can be used to determine which identifier to use for a specific purpose.

Allows users to make use of identifiers when the identifier system is not known.

Establishes the namespace for the value - that is, a URL that describes a set values that are unique.

There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers.

The portion of the identifier typically relevant to the user and which is unique within the context of the system.

If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the Rendered Value extension.

Time period during which identifier is/was valid for use.

Organization that issued/manages the identifier.

The Identifier.assigner may omit the .reference element and only contain a .display element reflecting the name or other textual information about the assigning organization.

A name associated with the person.

Person may have multiple names with different uses or applicable periods.

Need to be able to track the person by multiple names. Examples are your official name and a partner name.

unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

An Extension

R4B: Person.name additional types (HumanName) additional types from child elements (family, given, period, prefix, suffix, text, use)

Element Person.name is mapped to FHIR STU3 element Person.name as SourceIsBroaderThanTarget. The mappings for Person.name do not cover the following types: HumanName. The mappings for Person.name do not cover the following types based on type expansion: family, given, period, prefix, suffix, text, use. Person may have multiple names with different uses or applicable periods.

Identifies the purpose for this name.

This is labeled as "Is Modifier" because applications should not mistake a temporary or old name etc.for a current/permanent one. Applications can assume that a name is current unless it explicitly says that it is temporary or old.

The use of a human name

Allows the appropriate name for a particular context of use to be selected from among a set of names.

A full text representation of the name.

Can provide both a text representation and structured parts.

A renderable, unencoded form.

The part of a name that links to the genealogy. In some cultures (e.g. Eritrea) the family name of a son is the first name of his father.

Family Name may be decomposed into specific parts using extensions (de, nl, es related cultures).

Given name.

If only initials are recorded, they may be used in place of the full name. Not called "first name" since given names do not always come first.

Part of the name that is acquired as a title due to academic, legal, employment or nobility status, etc. and that appears at the start of the name.

Part of the name that is acquired as a title due to academic, legal, employment or nobility status, etc. and that appears at the end of the name.

Indicates the period of time when this name was valid for the named person.

Allows names to be placed in historical context.

A contact detail for the person, e.g. a telephone number or an email address.

Person may have multiple ways to be contacted with different uses or applicable periods. May need to have options for contacting the person urgently, and also to help with identification.

People have (primary) ways to contact them in some way such as phone, email.

unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

An Extension

R4B: Person.telecom additional types (ContactPoint) additional types from child elements (period, rank, system, use, value)

Element Person.telecom is mapped to FHIR STU3 element Person.telecom as SourceIsBroaderThanTarget. The mappings for Person.telecom do not cover the following types: ContactPoint. The mappings for Person.telecom do not cover the following types based on type expansion: period, rank, system, use, value. Person may have multiple ways to be contacted with different uses or applicable periods. May need to have options for contacting the person urgently and also to help with identification.

Telecommunications form for contact point - what communications system is required to make use of the contact.

Telecommunications form for contact point

The actual contact point details, in a form that is meaningful to the designated communication system (i.e. phone number or email address).

Additional text data such as phone extension numbers, or notes about use of the contact are sometimes included in the value.

Need to support legacy numbers that are not in a tightly controlled format.

Identifies the purpose for the contact point.

This is labeled as "Is Modifier" because applications should not mistake a temporary or old contact etc.for a current/permanent one. Applications can assume that a contact is current unless it explicitly says that it is temporary or old.

Use of contact point

Need to track the way a person uses this contact, so a user can choose which is appropriate for their purpose.

Specifies a preferred order in which to use a set of contacts. Contacts are ranked with lower values coming before higher values.

Note that rank does not necessarily follow the order in which the contacts are represented in the instance.

Time period when the contact point was/is in use.

Administrative Gender.

The gender may not match the biological sex as determined by genetics, or the individual's preferred identification. Note that for both humans and particularly animals, there are other legitimate possibilities than M and F, though the vast majority of systems and contexts only support M and F.

The gender of a person used for administrative purposes.

Needed for identification of the person, in combination with (at least) name and birth date. Gender of person drives many clinical processes.

The birth date for the person.

At least an estimated year should be provided as a guess if the real DOB is unknown.

Age of person drives many clinical processes, and is often used in performing identification of the person. Times are not included so as to not confuse things with potential timezone issues.

One or more addresses for the person.

Person may have multiple addresses with different uses or applicable periods.

May need to keep track of person's addresses for contacting, billing or reporting requirements and also to help with identification.

unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

An Extension

R4B: Person.address additional types (Address) additional types from child elements (city, country, district, line, period, postalCode, state, text, type, use)

Element Person.address is mapped to FHIR STU3 element Person.address as SourceIsBroaderThanTarget. The mappings for Person.address do not cover the following types: Address. The mappings for Person.address do not cover the following types based on type expansion: city, country, district, line, period, postalCode, state, text, type, use. Person may have multiple addresses with different uses or applicable periods.

The purpose of this address.

This is labeled as "Is Modifier" because applications should not mistake a temporary or old address etc.for a current/permanent one. Applications can assume that an address is current unless it explicitly says that it is temporary or old.

The use of an address

Allows an appropriate address to be chosen from a list of many.

Distinguishes between physical addresses (those you can visit) and mailing addresses (e.g. PO Boxes and care-of addresses). Most addresses are both.

The type of an address (physical / postal)

A full text representation of the address.

Can provide both a text representation and parts.

A renderable, unencoded form.

This component contains the house number, apartment number, street name, street direction, P.O. Box number, delivery hints, and similar address information.

home | work | temp | old - purpose of this address.

The name of the city, town, village or other community or delivery center.

The name of the administrative area (county).

District is sometimes known as county, but in some regions 'county' is used in place of city (municipality), so county name should be conveyed in city instead.

Sub-unit of a country with limited sovereignty in a federally organized country. A code may be used if codes are in common use (i.e. US 2 letter state codes).

A postal code designating a region defined by the postal service.

Country - a nation as commonly understood or generally accepted.

ISO 3166 3 letter codes can be used in place of a full country name.

Time period when address was/is in use.

Allows addresses to be placed in historical context.

An image that can be displayed as a thumbnail of the person to enhance the identification of the individual.

unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

An Extension

R4B: Person.photo additional types (Attachment) additional types from child elements (contentType, creation, data, hash, language, size, title, url)

Element Person.photo is mapped to FHIR STU3 element Person.photo as SourceIsBroaderThanTarget. The mappings for Person.photo do not cover the following types: Attachment. The mappings for Person.photo do not cover the following types based on type expansion: contentType, creation, data, hash, language, size, title, url.

Identifies the type of the data in the attachment and allows a method to be chosen to interpret or render the data. Includes mime type parameters such as charset where appropriate.

The mime type of an attachment. Any valid mime type is allowed.

Processors of the data need to be able to know how to interpret the data.

The human language of the content. The value can be any valid value according to BCP 47.

A human language.

Users need to be able to choose between the languages in a set of attachments.

The actual data of the attachment - a sequence of bytes. In XML, represented using base64.

The base64-encoded data SHALL be expressed in the same character set as the base resource XML or JSON.

The data needs to able to be transmitted inline.

An alternative location where the data can be accessed.

If both data and url are provided, the url SHALL point to the same content as the data contains. Urls may be relative references or may reference transient locations such as a wrapping envelope using cid: though this has ramifications for using signatures. Relative URLs are interpreted relative to the service url, like a resource reference, rather than relative to the resource itself. If a URL is provided, it SHALL resolve to actual data.

The data needs to be transmitted by reference.

The number of bytes of data that make up this attachment (before base64 encoding, if that is done).

The number of bytes is redundant if the data is provided as a base64binary, but is useful if the data is provided as a url reference.

Representing the size allows applications to determine whether they should fetch the content automatically in advance, or refuse to fetch it at all.

The calculated hash of the data using SHA-1. Represented using base64.

The hash is calculated on the data prior to base64 encoding, if the data is based64 encoded.

Included so that applications can verify that the contents of a location have not changed and so that a signature of the content can implicitly sign the content of an image without having to include the data in the instance or reference the url in the signature.

A label or set of text to display in place of the data.

Applications need a label to display to a human user in place of the actual data if the data cannot be rendered or perceived by the viewer.

The date that the attachment was first created.

This is often tracked as an integrity issue for use of the attachment.

The organization that is the custodian of the person record.

Need to know who recognizes this person record, manages and updates it.

unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

An Extension

R4B: Person.managingOrganization additional types from child elements (display, identifier, reference, type)

Element Person.managingOrganization is mapped to FHIR STU3 element Person.managingOrganization as SourceIsBroaderThanTarget. The mappings for Person.managingOrganization do not cover the following types based on type expansion: display, identifier, reference, type. The standard extension alternate-reference has been mapped as the representation of FHIR R4B element Person.managingOrganization with unmapped reference targets: Organization.

A reference to a location at which the other resource is found. The reference may be a relative reference, in which case it is relative to the service base URL, or an absolute URL that resolves to the location where the resource is found. The reference may be version specific or not. If the reference is not to a FHIR RESTful server, then it should be assumed to be version specific. Internal fragment references (start with '#') refer to contained resources.

Using absolute URLs provides a stable scalable approach suitable for a cloud/web context, while using relative/logical references provides a flexible approach suitable for use when trading across closed eco-system boundaries. Absolute URLs do not need to point to a FHIR RESTful server, though this is the preferred approach. If the URL conforms to the structure "/[type]/[id]" then it should be assumed that the reference is to a FHIR RESTful server.

An identifier for the other resource. This is used when there is no way to reference the other resource directly, either because the entity is not available through a FHIR server, or because there is no way for the author of the resource to convert a known identifier to an actual location. There is no requirement that a Reference.identifier point to something that is actually exposed as a FHIR instance, but it SHALL point to a business concept that would be expected to be exposed as a FHIR instance, and that instance would need to be of a FHIR resource type allowed by the reference.

When an identifier is provided in place of a reference, any system processing the reference will only be able to resolve the identifier to a reference if it understands the business context in which the identifier is used. Sometimes this is global (e.g. a national identifier) but often it is not. For this reason, none of the useful mechanisms described for working with references (e.g. chaining, includes) are possible, nor should servers be expected to be able resolve the reference. Servers may accept an identifier based reference untouched, resolve it, and/or reject it - see CapabilityStatement.rest.resource.referencePolicy.

When both an identifier and a literal reference are provided, the literal reference is preferred. Applications processing the resource are allowed - but not required - to check that the identifier matches the literal reference

Applications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it.

Plain text narrative that identifies the resource in addition to the resource reference.

This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it.

Whether this person's record is in active use.

Need to be able to mark a person record as not to be used because it was created in error.

Link to a resource that concerns the same actual person.

unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

May be used to represent additional information that is not part of the basic definition of the element. In order to make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

May be used to represent additional information that is not part of the basic definition of the element, and that modifies the understanding of the element that contains it. Usually modifier elements provide negation or qualification. In order to make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

The resource to which this actual person is associated.

unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

An Extension

R4B: Person.link.target

Element Person.link.target is mapped to FHIR STU3 element Person.link.target as SourceIsBroaderThanTarget. The standard extension alternate-reference has been mapped as the representation of FHIR R4B element Person.link.target with unmapped reference targets: Patient, Person, Practitioner, RelatedPerson.

A reference to a location at which the other resource is found. The reference may be a relative reference, in which case it is relative to the service base URL, or an absolute URL that resolves to the location where the resource is found. The reference may be version specific or not. If the reference is not to a FHIR RESTful server, then it should be assumed to be version specific. Internal fragment references (start with '#') refer to contained resources.

Using absolute URLs provides a stable scalable approach suitable for a cloud/web context, while using relative/logical references provides a flexible approach suitable for use when trading across closed eco-system boundaries. Absolute URLs do not need to point to a FHIR RESTful server, though this is the preferred approach. If the URL conforms to the structure "/[type]/[id]" then it should be assumed that the reference is to a FHIR RESTful server.

An identifier for the other resource. This is used when there is no way to reference the other resource directly, either because the entity is not available through a FHIR server, or because there is no way for the author of the resource to convert a known identifier to an actual location. There is no requirement that a Reference.identifier point to something that is actually exposed as a FHIR instance, but it SHALL point to a business concept that would be expected to be exposed as a FHIR instance, and that instance would need to be of a FHIR resource type allowed by the reference.

When an identifier is provided in place of a reference, any system processing the reference will only be able to resolve the identifier to a reference if it understands the business context in which the identifier is used. Sometimes this is global (e.g. a national identifier) but often it is not. For this reason, none of the useful mechanisms described for working with references (e.g. chaining, includes) are possible, nor should servers be expected to be able resolve the reference. Servers may accept an identifier based reference untouched, resolve it, and/or reject it - see CapabilityStatement.rest.resource.referencePolicy.

When both an identifier and a literal reference are provided, the literal reference is preferred. Applications processing the resource are allowed - but not required - to check that the identifier matches the literal reference

Applications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it.

Plain text narrative that identifies the resource in addition to the resource reference.

This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it.

Level of assurance that this link is actually associated with the target resource.

The level of confidence that this link represents the same actual person, based on NIST Authentication Levels.