Australian postcodes are sorting information. They are often linked with one area (e.g. 6160 belongs only to Fremantle, Western Australia). But sometimes they can be quite complex, especially in country areas (e.g. 2570 belongs to twenty-two towns and suburbs around Camden, New South Wales). The south-western Victoria 3221 postcode of the Geelong Mail Centre also includes twenty places around Geelong with very few people. This means that mail for these places is not fully sorted until it gets to Geelong. Some postcodes cover large populations (e.g., postcode 4350 serving some 100,000 people in the City of Toowoomba), while other postcodes have much smaller populations, even in urban areas. The postcode numbers range from as low as 0200 (for the Australian National University) to 9729 (mail addressed to the Gold Coast City Council).