What is the difference between canonical and alias addresses?

The Addressfinder dataset consists of two sorts of addresses:

Canonical Addresses

Canonical addresses are the official addresses that are supplied to us by the PSMA or Australia Post. They contain the correct street name, the correct suburb and are spelled correcty. By default, the Addressfinder widget always selects the canonical addresses when performing autocomplete and verification operations.

Alias Addresses

Alias addresses are addresses with unofficial address components. These may include nearby suburbs, commonly misspelled street names or older street names which have since been superseded. All of these potential alias addresses are included in the Addressfinder database in order to enable the user to find and select them. You will not receive this inaccurate address however as the default action of the widget is to return the (corrected) canonical address.

API Responses

The Addressfinder APIs will return both an id and a canonical_address_id. API developers can choose to mimic the Addressfinder widget behaviour by using the canonical_address_id field to query the Address Metadata API.