This page is part of the FHIR Specification (v0.01: Historical Archive Draft). The current version which supercedes this version is 4.0.1. For a full list of available versions, see the Directory of published versions

# Terminologies

Throughout the FHIR specification, many elements are assigned a type of either code, Coding, or CodeableConcept. These elements are bound to a "Concept Domain", which defines the set of concepts that may be associated with the element. Each Concept Domain has a formal definition, and a binding type that may define a particular set of acceptable concepts:

Code List | The concept is directly bound to a code list defined in this specification (mostly used with elements of type "code"). In some circumstances, other additional codes may be used (not for elements with type "code")
External | The possible list of codes (concepts) is defined by an external specification, usually ISO or W3C. A reference is provided
Preferred | The concept domain is bound directly to an external coding system, and values from this coding system must be use if appropriate values exist
Unbound | The FHIR specification does not bind the concept domain to any particular set of concepts (a value set). Instead, jurisdictions, Institions, projects or applications bind the concept domain. Within the unbound concept domains, FHIR may recommend a particular value set (or coding system), or suggest values as illustrative

Note that this approach is based on the framework defined in the HL7 V3 core principles in section 5.1. Also note that when a CodeableConcept has a concept domain, this means that one of the codes in the coding list meet the binding of the concept domain, and all the codes must conform to the definition of the concept domain.

## Named Systems List

This specification defines the following names (URIs) as fiexed names that may be used in the system element of the Identifier, Coding or data types.

URI | Source | Comment
--- | --- | ---
Code Systems
http://snomed.info | SNOMED-CT: (IHTSDO) | The version, module etc may be appended to this uri following the IHTSDO specifications OID=2.16.840.1.113883.6.96
urn:hl7-org:sid/loinc | LOINC (LOINC.org) | The LOINC sid can also be used to indicate a LOINC property value by append one of the following values to the URL:
/property | PROPERTY
/time-aspect | TIME_ASPCT
/system | SYSTEM
/scale | SCALE_TYPE
/method | METHOD_TYPE
/class | CLASS
The acceptable values for these URLs are the literal values found in the definition of LOINC for the given column name. The version of LOINC may be appended to this uri like so: urn:hl7-org:sid/loinc?v=2.36 OID=2.16.840.1.113883.6.1.
urn:hl7-org:sid/ucum | UCUM: (UnitsOfMeasure.org) | Generally used in the Quantity Data Type OID=2.16.840.1.113883.6.8
urn:hl7-org:sid/icd-10 | ICD-10 International (WHO) | OID=2.16.840.1.113883.6.3
urn:hl7-org:sid/icd-9 | ICD-9 USA (CDC) | OID=2.16.840.1.113883.6.42
urn:hl7-org:sid/v2-[X] | Version 2 table code | [X] is the 4 digit identifier for a table. i.e. urn:hl7-org:sid/v2-0203 OID=2.16.840.1.113883.12.[X]
urn:hl7-org:sid/iso-639 | Language Codes as defined in (ISO 639) | 3 letter codes known as 639-3 OID=1.0.639.3
urn:hl7-org:sid/iso-4217 | Currency Codes as defined in (ISO 4217) | 3 digit currency designators OID=1.0.4217
urn:hl7-org:sid/atc | Anatomical Therapeutic Chemical Classification System (WHO) | OID=2.16.840.1.113883.6.73
Identifier Systems
urn:hl7-org:sid/uri | URIs (W3C) | As defined by various applicable RFCs including X No OID
urn:hl7-org:sid/oid | OIDs | The identifier is an OID itself
urn:hl7-org:sid/uuid | UUIDs | Also called GUIDs No OID
urn:hl7-org:sid/us-ssn | SSN (W3C) | SSN for USA. Represented with dashes removed OID=2.16.840.1.113883.4.1

## Internal Code Systems

In addition to this, a number of code sytems are defined informally through the specification. This table enumerates them, and assigns sid and OID values for them, though these are not generally used directly in this specification:

Special Values | urn:hl7-org:sid/fhir/special-values | 2.16.840.1.113883.6.305
Resource Types | urn:hl7-org:sid/fhir/resources | 2.16.840.1.113883.6.306
Logical Interactions (RESTful framework) | urn:hl7-org:sid/fhir/interactions | 2.16.840.1.113883.6.308
Message Events (Messaging framework) | urn:hl7-org:sid/fhir/message-events | 2.16.840.1.113883.6.307
Data Absent Reason | urn:hl7-org:sid/fhir/data-absent-reason | 2.16.840.1.113883.6.309

Note that all the codes in these code systems are case sensitive, and must be used in lowercase.

## Special Values

Internally defined codes useful throughout the specification where Coding or CodeableConcept is used. These are defined by the code system "urn:hl7-org:sid/fhir/special-values" which has OID 2.16.840.1.113883.6.305.

true | Boolean true
false | Boolean false
trace | The content is greater than zero, but too small to be quantified (used in formulations)
sufficient | The specific quantity is not known, but is known to be non-zero and is not specified because it makes up the bulk of the material. (e.g. 'Add 10mg of ingredient X, 50mg of ingredient Y, and sufficient quantity of water to 100mL.' The null flavor would be used to express the quantity of water. )
withdrawn | The correct value is no longer available

## Resource Types

In several places, the resource types themselves are used as codes, with the sid, where required, of "urn:hl7-org:sid/fhir/resource-types". This is a formal list of such codes:

Conformance | A conformance statement returned by request in an RESTful framework
Document | A documentation of clinical observations and services that are aggregated together into a single statement of clinical meaning that establishes it's own context. A clinical document is composed of a set of resources that include both human and computer readable portions. A human must attest to the accuracy of the human readable portion, and may authenticate and/or sign the entire whole
Message | A message that contains FHIR resources
Animal | An animal that has relevance to the care process -usually this is for animals that are patients.
Agent | A person who represents an organisation, and is authorised to perform actions on it's behalf
MessageConformance | A conformance statement about how an application uses FHIR messaging
Organization | For any organization/institution/government department that has relevance to the care process
Prescription | Directions provided by a prescribing practitioner for a specific medication to be administered to an individual
Profile | A Resource Profile - a statement of constraint on one or more Resources and/or Concept Domains
InterestOfCare | Yet to be defined
Admission | Yet to be defined
Specimen | Yet to be defined
Device | Yet to be defined
Patient | A patient is a person or animal that is receiving care
Group | Yet to be defined
Person | A person who is involved in the healthcare process
LabReport | The findings and interpretation of pathology tests performed on tissues and body fluids. This is typically done in a laboratory but may be done in other environments such as at the point of care
DocumentConformance | A conformance statement about how one or more FHIR documents

This is an old version of FHIR retained for archive purposes. Do not use for anything else
Implementers are welcome to experiment with the content defined here, but should note that the contents are subject to change without prior notice.
© HL7.org 2011 - 2012. FHIR v0.01 generated on Mon, May 14, 2012 09:48+1000.