The code that is to be located. If a code is provided, a system must be provided

The system for the code that is to be located

The version of the system, if one was provided in the source data

A coding to look up

The date for which the information should be returned. Normally, this is the current conditions (which is the default value) but under some circumstances, systems need to acccess this information as it would have been in the past. A typical example of this would be where code selection is constrained to the set of codes that were available when the patient was treated, not when the record is being edited. Note that which date is appropriate is a matter for implementation policy.

The requested language for display (see $expand.displayLanguage) CodeSystem.concept.designation.language)

A property that the client wishes to be returned in the output. If no properties are specified, the server chooses what to return. The following properties are defined for all code systems: url, name, version (code system info) and code information: display, definition, designation, parent and child, and for designations, lang.X where X is a designation language code. Some of the These properties are returned explicit explicitly in named out parameters (when with matching names, or in designations. In addition, any property codes defined by this specification or by the names match), CodeSystem ( CodeSystem.property.code ) are allowed, and the rest (except for lang.X) these are returned in the out parameter property

Supplements to take into account when performing the $lookup operation. The supplements must be for the same CodeSystem. By default, supplements for the code system are not automatically included except where they provide additional designations that may be indicated by, for example, the displayLanguage parameter group

A display name for the code system

The version that these details are based on

The preferred display for this concept

A statement of the meaning of the concept from the code system

Additional representations for this concept

The language this designation is defined for

A code that details how this designation would be used

Additional codes that detail how this designation would be used (if there is more than one)

The text value for this designation

One or more properties that contain additional information about the code, including status. For complex terminologies (e.g. SNOMED CT, LOINC, medications), these properties serve to decompose the code

Identifies the property returned

The value of the property returned

Human Readable representation of the property value (e.g. display for a code)

If information from a supplement is included as a property (e.g. any additional property or property value), then this parameter must assert the url of the supplement.

Nested Properties (mainly used for SNOMED CT decomposition, for relationship Groups)

Identifies the sub-property returned

The value of the sub-property returned

Human Readable representation of the property sub-property value (e.g. display for a code)

If information from a supplement is included as a subproperty (e.g. any additional subproperty or subproperty value), then this parameter must assert the url of the supplement.