Demographics and other administrative information about an individual or animal receiving care or other health-related services.

A reference to a set of rules that were followed when the resource was constructed, and which must be understood when processing the content. Often, this is a reference to an implementation guide that defines the special rules along with other profiles etc.

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. Often, when used, the URL is a reference to an implementation guide that defines these special rules as part of its narrative along with other profiles, value sets, etc.

These resources do not have an independent existence apart from the resource that contains them - they cannot be identified independently, nor can they have their own independent transaction scope. This is allowed to be a Parameters resource if and only if it is referenced by a resource that provides context/meaning.

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. Contained resources may have profiles and tags in their meta elements, but SHALL NOT have security labels.

An Extension

The patient's legal status as citizen of a country.

An Extension

An Extension

Source of the definition for the extension code - a logical name or a URL.

The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.

Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).

Period when citizenship was effective.

An Extension

Source of the definition for the extension code - a logical name or a URL.

The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.

Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).

Source of the definition for the extension code - a logical name or a URL.

The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.

Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).

HL7® Austria FHIR® Core Extension for the religion (registered in Austria) of a patient. The extension is used to encode the religious confession of a patient (only confessions registered in Austria). Furthermore, it uses the official [HL7 AT CodeSystem](https://termpub.gesundheit.gv.at:443/TermBrowser/gui/main/main.zul?loadType=CodeSystem&loadName=HL7 AT ReligionAustria) for religion and is therefore aligned with the ELGA ValueSet, respectively.

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 and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and managable, 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.

Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

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.

Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

An identifier for this patient.

Patients are almost always assigned specific numerical identifiers.

The purpose of this identifier.

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.

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

An identifier for this patient.

Patients are almost always assigned specific numerical identifiers.

The purpose of this identifier.

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.

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

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

Identifier.system is always case sensitive.

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 http://hl7.org/fhir/StructureDefinition/rendered-value). Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processer to be confident that non-case-sensitive processing is safe.

An identifier for this patient.

Patients are almost always assigned specific numerical identifiers.

The purpose of this identifier.

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.

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

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

Identifier.system is always case sensitive.

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 http://hl7.org/fhir/StructureDefinition/rendered-value). Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processer to be confident that non-case-sensitive processing is safe.

An identifier for this patient.

Patients are almost always assigned specific numerical identifiers.

The purpose of this identifier.

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.

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

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

Identifier.system is always case sensitive.

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 http://hl7.org/fhir/StructureDefinition/rendered-value). Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processer to be confident that non-case-sensitive processing is safe.

Whether this patient record is in active use. Many systems use this property to mark as non-current patients, such as those that have not been seen for a period of time based on an organization's business rules.

It is often used to filter patient lists to exclude inactive patients

Deceased patients may also be marked as inactive for the same reasons, but may be active for some time after death.

If a record is inactive, and linked to an active record, then future patient/record updates should occur on the other patient.

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

A name associated with the individual.

A patient may have multiple names with different uses or applicable periods. For animals, the name is a "HumanName" in the sense that is assigned and used by humans and has the same patterns. Animal names may be communicated as given names, and optionally may include a family name.

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

Identifies the purpose for this name.

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.

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 parts. Initials may be separated into multiple given names but often aren't due to paractical limitations. This element is 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.

Administrative Gender - the gender that the patient is considered to have for administration and record keeping purposes.

The gender might 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 male and female, though the vast majority of systems and contexts only support male and female. Systems providing decision support or enforcing business rules should ideally do this on the basis of Observations dealing with the specific sex or gender aspect of interest (anatomical, chromosomal, social, etc.) However, because these observations are infrequently recorded, defaulting to the administrative gender is common practice. Where such defaulting occurs, rule enforcement should allow for the variation between administrative and biological, chromosomal and other gender aspects. For example, an alert about a hysterectomy on a male should be handled as a warning or overridable error, not a "hard" error. See the Patient Gender and Sex section for additional information about communicating patient gender and sex.

The gender of a person used for administrative purposes.

Needed for identification of the individual, in combination with (at least) name and birth date.

An Extension

HL7® Austria FHIR® Core Extension for the administrative gender of a person (Patient, Practitioner, ...). The extension is used to add the missing codes and is applied in case the code for administrative gender itself is set to 'other'.

The date of birth for the individual.

Partial dates are allowed if the specific date of birth is unknown. There is a standard extension "patient-birthTime" available that should be used where Time is required (such as in maternity/infant care systems).

Age of the individual drives many clinical processes.

Indicates if the individual is deceased or not.

If there's no value in the instance, it means there is no statement on whether or not the individual is deceased. Most systems will interpret the absence of a value as a sign of the person being alive.

The fact that a patient is deceased influences the clinical process. Also, in human communication and relation management it is necessary to know whether the person is alive.

Indicates if the individual is deceased or not.

If there's no value in the instance, it means there is no statement on whether or not the individual is deceased. Most systems will interpret the absence of a value as a sign of the person being alive.

The fact that a patient is deceased influences the clinical process. Also, in human communication and relation management it is necessary to know whether the person is alive.

Indicates if the individual is deceased or not.

If there's no value in the instance, it means there is no statement on whether or not the individual is deceased. Most systems will interpret the absence of a value as a sign of the person being alive.

The fact that a patient is deceased influences the clinical process. Also, in human communication and relation management it is necessary to know whether the person is alive.

An address expressed using postal conventions (as opposed to GPS or other location definition formats). This data type may be used to convey addresses for use in delivering mail as well as for visiting locations which might not be valid for mail delivery. There are a variety of postal address formats defined around the world. The ISO21090-codedString may be used to provide a coded representation of the contents of strings in an Address.

Note: address is intended to describe postal addresses for administrative purposes, not to describe absolute geographical coordinates. Postal addresses are often used as proxies for physical locations (also see the Location resource).

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

The purpose of this address.

Applications can assume that an address is current unless it explicitly says that it is temporary or old.

The use of an address (home / work / etc.).

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

Specifies the entire address as it should be displayed e.g. on a postal label. This may be provided instead of or as well as the specific parts.

Can provide both a text representation and parts. Applications updating an address SHALL ensure that when both text and parts are present, no content is included in the text that isn't found in a part.

A renderable, unencoded form.

This component contains the street name, street number, floor and/or door number or additonal information (e.g. street direction, P.O. Box number, delivery hints, and similar address information). This information can be split into structured values in the line-components each defined by international ISO extensions. If these extensions are used then the information they contain has to be written in a concatenated way in the line element itself as well. This makes the usage easier for systems which don't use address data in a structured way.

Name of the street without the street number

Number of the street without the street name

Floor and/or door number

Additional information about the street address

The name of the city, town, suburb, 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 (e.g. 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 2- or 3- letter codes MAY be used in place of a human readable country name.

Time period when address was/is in use.

Allows addresses to be placed in historical context.

Indicates whether the patient is part of a multiple (boolean) or indicates the actual birth order (integer).

Where the valueInteger is provided, the number is the birth number in the sequence. E.g. The middle birth in triplets would be valueInteger=2 and the third born would have valueInteger=3 If a boolean value was provided for this triplets example, then all 3 patient records would have valueBoolean=true (the ordering is not indicated).

For disambiguation of multiple-birth children, especially relevant where the care provider doesn't meet the patient, such as labs.

Indicates whether the patient is part of a multiple (boolean) or indicates the actual birth order (integer).

Where the valueInteger is provided, the number is the birth number in the sequence. E.g. The middle birth in triplets would be valueInteger=2 and the third born would have valueInteger=3 If a boolean value was provided for this triplets example, then all 3 patient records would have valueBoolean=true (the ordering is not indicated).

For disambiguation of multiple-birth children, especially relevant where the care provider doesn't meet the patient, such as labs.

Indicates whether the patient is part of a multiple (boolean) or indicates the actual birth order (integer).

Where the valueInteger is provided, the number is the birth number in the sequence. E.g. The middle birth in triplets would be valueInteger=2 and the third born would have valueInteger=3 If a boolean value was provided for this triplets example, then all 3 patient records would have valueBoolean=true (the ordering is not indicated).

For disambiguation of multiple-birth children, especially relevant where the care provider doesn't meet the patient, such as labs.

Image of the patient.

Guidelines:

• Use id photos, not clinical photos.
• Limit dimensions to thumbnail.
• Keep byte count low to ease resource updates.

Many EHR systems have the capability to capture an image of the patient. Fits with newer social media usage too.

Patient's nominated care provider.

This may be the primary care provider (in a GP context), or it may be a patient nominated care manager in a community/disability setting, or even organization that will provide people to perform the care provider roles. It is not to be used to record Care Teams, these should be in a CareTeam resource that may be linked to the CarePlan or EpisodeOfCare resources. Multiple GPs may be recorded against the patient for various reasons, such as a student that has his home GP listed along with the GP at university during the school semesters, or a "fly-in/fly-out" worker that has the onsite GP also included with his home GP to remain aware of medical issues.

Jurisdictions may decide that they can profile this down to 1 if desired, or 1 per type.

Organization that is the custodian of the patient record.

There is only one managing organization for a specific patient record. Other organizations will have their own Patient record, and may use the Link property to join the records together (or a Person resource which can include confidence ratings for the association).

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

Link to a Patient or RelatedPerson resource that concerns the same actual individual.

There is no assumption that linked patient records have mutual links.

There are multiple use cases:

• Duplicate patient records due to the clerical errors associated with the difficulties of identifying humans consistently, and
• Distribution of patient information across multiple servers.

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 in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can 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.

Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

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.

Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

Link to a Patient or RelatedPerson resource that concerns the same actual individual.

Referencing a RelatedPerson here removes the need to use a Person record to associate a Patient and RelatedPerson as the same individual.

The type of link between this patient resource and another patient resource.

The type of link between this patient resource and another Patient resource, or Patient/RelatedPerson when using the seealso code

Demographics and other administrative information about an individual or animal receiving care or other health-related services.

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

Within the context of the FHIR RESTful interactions, the resource has an id except for cases like the create and conditional update. Otherwise, the use of the resouce id depends on the given use case.

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

A reference to a set of rules that were followed when the resource was constructed, and which must be understood when processing the content. Often, this is a reference to an implementation guide that defines the special rules along with other profiles etc.

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. Often, when used, the URL is a reference to an implementation guide that defines these special rules as part of its narrative along with other profiles, value sets, etc.

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).

IETF language tag for a human language

A human-readable narrative that contains a summary of the resource and can 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 a 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.

These resources do not have an independent existence apart from the resource that contains them - they cannot be identified independently, nor can they have their own independent transaction scope. This is allowed to be a Parameters resource if and only if it is referenced by a resource that provides context/meaning.

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. Contained resources may have profiles and tags in their meta elements, but SHALL NOT have security labels.

An Extension

The patient's legal status as citizen of a country.

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. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can 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.

An Extension

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

An Extension

Source of the definition for the extension code - a logical name or a URL.

The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.

Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).

Period when citizenship was effective.

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

An Extension

Source of the definition for the extension code - a logical name or a URL.

The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.

Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).

Source of the definition for the extension code - a logical name or a URL.

The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.

Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).

HL7® Austria FHIR® Core Extension for the religion (registered in Austria) of a patient. The extension is used to encode the religious confession of a patient (only confessions registered in Austria). Furthermore, it uses the official [HL7 AT CodeSystem](https://termpub.gesundheit.gv.at:443/TermBrowser/gui/main/main.zul?loadType=CodeSystem&loadName=HL7 AT ReligionAustria) for religion and is therefore aligned with the ELGA ValueSet, respectively.

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 and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and managable, 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.

Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

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.

Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

An identifier for this patient.

Patients are almost always assigned specific numerical identifiers.

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. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can 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.

The purpose of this identifier.

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.