A knowledge request is a formal request for the evaluation of some artifact or group of artifacts as part of a clinical quality workflow. This may be part of a direct, point-of-care, workflow, such as a decision support request, or it may be part of a clinical quality assessment such as a request to calculate a particular quality measure.

The id of the request. If this id if provided by the client, the server must provide this value back to the client as part of the response.

The only time that a resource does not have an id is when it is being submitted to the server using a create operation. Bundles always have an id, though it is usually a generated UUID.

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.

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 as much as possible.

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-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.

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.

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The date and time of the request, with respect to the initiator.

Indicates that the evaluation should be performed as though it was the given date and time. The most direct implication of this is that references to "Now" within the evaluation logic of the module should result in this value. In addition, wherever possible, the data accessed by the module should appear as though it was accessed at this time. The evaluateAtDateTime value may be any time in the past or future, enabling both retrospective and prospective scenarios. If no value is provided, the requestDateTime is assumed.

The input parameters for a request, if any. These parameters are used to provide patient-independent information to the evaluation. Patient-specific information is either accessed directly as part of the evaluation (because the evaluation engine and the patient-data are co-located) or provided as part of the operation input in the form of resources.

A reference to a knowledge module involved in an interaction.

Identifier assigned to the resource for business purposes, outside the context of FHIR.

Identifies the 'type' of resource - equivalent to the resource name for other resources.

Must be able to distinguish different types of "basic" resources.

Because resource references will only be able to indicate 'Basic', the type of reference will need to be specified in a Profile identified as part of the resource. Refer to the resource notes section for information on appropriate terminologies for this code.

Identifies the patient, practitioner, device or any other resource that is the "focus" of this resoruce.

Needed for partitioning the resource by Patient.

Optional as not all resources potential resources will have subjects. Resources associated with multiple subjects can handle this via extension.

Indicates who was responsible for creating the resource instance.

Needed for partitioning the resource.

Identifies when the resource was first created.

Allows ordering resource instances by time.