A Search Parameter that defines a named search item that can be used to search/filter on a resource.

In FHIR, search is not performed directly on a resource (by XML or JSON path), but on a named parameter that maps into the resource content.

An absolute URL at which this search parameter is (or will be) published, and which is used to reference this profile in conformance statements.

To allow referencing and reusing search parameter definitions under other names on operational systems (in case of name clash).

The name of the standard or custom search parameter.

This is the name to be used for this parameter in the search parameters in the URL.

The name of the individual or organization that published the search parameter.

Helps establish the "authority/credibility" of the search parameter. May also allow for contact.

Usually an organization, but may be an individual. This item SHOULD be populated unless the information is available from context.

Contacts to assist a user in finding and communicating with the publisher.

May be a web site, an email address, a telephone number (tel:), etc.

The name of an individual to contact regarding the search parameter.

If there is no named individual, the telecom is for the organization as a whole.

Contact details for individual (if a name was provided) or the publisher.

The Scope and Usage that this search parameter was created to meet.

The status of this search parameter definition.

This is not intended for use with actual conformance statements, but where conformance statements are used to describe possible or desired systems.

A flag to indicate that this search parameter definition is authored for testing purposes (or education/evaluation/marketing), and is not intended to be used for genuine usage.

Allows filtering of search parameter definitions that are appropriate for use vs. not.

The date (and optionally time) when the search parameter definition was published.

The base resource type that this search parameter refers to.

The type of value a search parameter refers to, and how the content is interpreted.

A description of the search parameters and how it used.

An XPath expression that returns a set of elements for the search parameter.

Note that the elements returned by the XPath are sometimes complex elements where logic is required to determine quite how to handle them. E.g. CodeableConcepts may contain text and/or multiple codings, where the codings themselves contain a code and a system.

Types of resource (if a resource is referenced).