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.

The purpose of this address.

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

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

The use of an address.

Distinguishes between physical addresses (those you can visit) and mailing addresses (e.g. PO Boxes and care-of addresses). Most addresses are both.

The definition of Address states that "address is intended to describe postal addresses, not physical locations". However, many applications track whether an address has a dual purpose of being a location that can be visited as well as being a valid delivery destination, and Postal addresses are often used as proxies for physical locations (also see the Location resource).

The type of an address (physical / postal).

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.

A renderable, unencoded form.

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.

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).

Note that FHIR strings SHALL NOT exceed 1MB in size

A postal code designating a region defined by the postal service.

Note that FHIR strings SHALL NOT exceed 1MB in size

Country - a nation as commonly understood or generally accepted.

ISO 3166 3 letter codes can 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.

A Period specifies a range of time; the context of use will specify whether the entire range applies (e.g. "the patient was an inpatient of the hospital for this time range") or one value from the range applies (e.g. "give to the patient between these two times").

Period is not used for a duration (a measure of elapsed time). See Duration.