1. Overview

1.1. Data product specification title

G-NAF Product Description

1.2. Reference date

May 2021

1.3. Informal description of the data product

G-NAF (Geocoded National Address File) is a trusted index of Australian address information. It contains the state, suburb, street, number and coordinate reference (or “geocode”) for street addresses in Australia. G-NAF does not contain any personal information or details relating to an individual or business. G-NAF uses existing and recognised address sources (referred to as contributors) from the state and territory government land records and Commonwealth government agencies. The Mesh Block data is sourced from the Australian Bureau of Statistics (ABS) and is part of their Australian Statistical Geography Standard (ASGS). A rigorous process is used that involves textual address comparison, matching and geospatial validation to provide both national consistency and national coverage.

1.4. Responsible party

Geoscape Australia Limited (Geoscape)
Unit 6, 113 Canberra Avenue, GRIFFITH ACT 2603 Australia
T: +61 2 6260 9000
E: support@geoscape.com.au
URL: http://www.geoscape.com.au
ABN: 23 089 912 710

1.5. Language

English

1.6. Topic category

Address files for urban, rural and locality areas within Australia.

1.7. Distribution Format

PDF

1.8. Glossary

Geoscape maintains a glossary of common terms with their definitions and also includes acronyms and abbreviations that are commonly used in relation to Geoscape products and services. The glossary is available at the Geoscape website at https://geoscape.com.au/documentation/glossary-and-terms/

The following list defines some of the terms used by Geoscape for G-NAF but is not necessarily the same definition as used by others.

Glossary

Term

Definition

Address

A structured label for any place that could deliver or receive a good or service.

Address Contributor

Supplier of address information to G‑NAF.

Address Level Geocode

An address in G‑NAF that has a parcel level geocode (i.e. a geocode reliability code of 2). Also referred to as a “parcel level” or “property level” address. The address will have one or more address site geocodes.

Alias Address (or Alternate Address)

Another label for a Principal Address which may differ because of a variation in some or all address components (i.e. numbers, levels, street name, locality name). An Alias Address will share the same location as the Principal Address. Association with Principal Address may be provided by an Address Contributor or determined programmatically.

Building Name

A building or property name that is associated with an address. The name is typically free text and is not unique to any address.

Class

Description of a set of objects that share the same attributes, operations, methods, relationships, and semantics [UML].

Note: A class does not always have an associated geometry (e.g. the metadata class).

Confidence Level

G‑NAF is currently built from three national address datasets. The confidence level of an address indicates the level of usage of each address by the contributor address datasets.

Contributor Data

Address datasets held and maintained by organisations external to Geoscape that is being made available for building and maintaining G‑NAF.

Event

Characteristic of a feature measured within an object without modifying the associated geometry.

Feature

Abstraction of real-world phenomena.

Feature Attribute

Characteristic of a feature (e.g. name of an area).

Gap Geocode

A geocode created programmatically based on address ranging in the absence of a geocode being allocated to a specific property. This geocode may not necessarily lie within a property polygon.

Geocode

A point feature for an address spatially defined by a coordinate. In G‑NAF, an address may have multiple geocodes representing various real-world features (e.g. parcel, property, building centroid, street centroid, locality centroid, etc.) associated with a physical address. The geographic coordinates are expressed as latitude/longitude in decimal degrees.

Geocode Level Type

The geocode level type indicates which geocodes have been assigned to an address. Every address within G‑NAF must have a locality level geocode. Addresses may also have a street level geocode, and an address level geocode.

Geocode Type

The type of address level geocode for an address, e.g. BUILDING CENTROID. An address can have multiple types of address level geocodes.

Geocode Priority

G‑NAF can assign multiple geocodes to an address. The geocode priority is a priority order established by Geoscape to enable a default geocode to be assigned to each address which represents the geocode of the highest precision currently assigned to an address.

Geocode Reliability

Refers to the geocode precision and is linked to how the geocode was generated.

G‑NAF Merge Criteria

Those components of an address string used by the G‑NAF process to uniquely identify an address.

Jurisdiction

Reference to a State or Territory Government.

Locality

A named geographical area defining a community or area of interest, which may be rural or urban in character. Usually known as a Suburb in an urban area. The localities used in G‑NAF are the gazetted localities as provided by the respective jurisdictions.

Locality Alias

Another recognised name for a gazetted locality name. Could be misspellings, historic authoritative names or unauthoritative names.

Other Territories

Refers to external Territories of Australia included within the Geoscape datasets: Christmas Island, Cocos (Keeling) Islands, Norfolk Island and Jervis Bay.

Mesh Blocks

Mesh Blocks are the smallest geographic region in the Australian Statistical Geography Standard (ASGS), and the smallest geographical unit for which Census data is available.

Object

An entity with a well-defined boundary and identity that encapsulates state and behaviour [UML Semantics].

Note: An object is an instance of a class.

Package

Grouping of a set of classes, relationships, and even other packages to organise the model into more abstract structures.

Postcodes

Postcodes are allocated to geographic areas to facilitate the efficient processing and delivery of mail.

Primary Postcodes

Primary postcodes are unique integers based on the postcodes used to differentiate between gazetted localities within a jurisdiction that shares the same name. They may not necessarily be coincident with the postcode for any area.

Primary Address

A Primary Address is a principal address that contains all the components of an address except flat number or level number information. Where flat number or level number information exists for an address, then this forms part of a Secondary Address and a linkage made to the Primary Address. Alternatively, a Primary Address can be linked to one or more Secondary Addresses by Geoscape where identified by an address contributor (e.g. involves private road in complex development, public housing estates etc.)

Principal Address

Accepted label for an Address which may have zero, one or more than one associated Alias Address.

Geoscape Online Data Delivery System

A suite of applications to store, quality assure and distribute Geoscape’s datasets.

Reference Data

Each address entering G‑NAF is tested to ensure it can be matched against the geospatial region to which it relates: state, locality and street. The datasets used for this geospatial verification are:

  • State and Territory Boundaries for Australia (State Boundaries)

  • Gazetted Locality Boundaries for Australia (Localities).

  • National Road Centreline Dataset (Roads)

These three datasets are commonly referred to as the Reference Data.

Rules

Rules are at times applied to contributor addresses as part of the G‑NAF processing where errors are identified in the addresses such as the incorrect spelling of street names, incorrect street types or incorrect localities. The application of these rules generates alias street localities or localities, depending on the rule applied.

Secondary Address

A Secondary Address is any address where flat number or level number information is not null, i.e. includes prefix, number or suffix. Alternatively, a Secondary Address can be linked to a Primary Address by Geoscape where identified by an address contributor (e.g. involves private road in complex development, public housing estates etc.).

Street (or Road)

An in-use name for a street name that exists within Geoscape’s National Road Centreline Dataset (i.e. reference dataset) within Geoscape Roads.

Street Locality

A Street or Road within a particular Locality, e.g. Smith St Melbourne VIC 3000. A street is unique to a locality. If it crosses a locality boundary, that segment receives a different street_locality_pid and is treated as another street.

Street Locality Alias

A Street or Road within a particular Locality that is an alternative name for a Street Locality Address.

Street Alias

In use name for a Street name not existing within Geoscape’s Road centreline dataset (i.e. reference dataset).

Quality

Data is of the highest quality reflective at the time and fields provided. Key factors are timeliness, consistency and completeness.

1.10. Privacy

Geoscape products and services should not contain any personal names or other personal information. Geoscape undertakes reasonable data cleansing steps as part of its production processes to ensure that is the case. If you think that personal information may have inadvertently been included in Geoscape products or services, please contact support@geoscape.com.au

1.11. Addressing standards

Australia has two national standards applicable to addressing:

  • AS/NZS 4819:2011 Geographic information—Rural and urban addressing

  • AS4590:2006 Interchange of Client Information.

1.12. About AS/NZ 4819:2011

The standard AS/NZ 4819:2011 is intended for use by agencies that are responsible for addressing. The goal of AS/NZ 4819:2011 is to specify requirements for assigning addresses that can be readily and unambiguously identified and located. To achieve this goal, the objectives of the standard are:

  • Localities are to enable addresses to be uniquely and clearly identified

  • Assigned names for roads or other primary means of access enable addresses to

be readily and uniquely identified

  • Assigned address numbering enables address sites to be readily located

  • Signage enables assigned addresses to be readily identified and located

  • Address information enables sites to be readily located.

1.13. About AS4590:2006

The standard AS4590:2006 sets out requirements of data elements for the interchange of client information. There are several elements specific to addressing. As G-NAF contains both old and new addresses, it is more closely related to the structure in AS4590:2006.

1.14. About the National Address Management Framework

The National Address Management Framework (NAMF) has been developed as a national, coordinated approach to address management. It is a consistent, standards-based framework which will guide the process for verifying addresses and provide a standard for exchange of address data. Appendix A sets out the relationship between G-NAF, AS450:2006 and NAMF fields.