The Canada Postal Points File links postal code points to census geography by establishing a link between the FSALDU and the Dissemination Area (DA).
There are instances where a postal code may serve customers in more than one DA. In order to maintain all postal code-census geography links, multiple records need to be created. These multiple postal code records provide alternate postal code coordinates and linkage to census geography to supplement the single most representative coordinates and geography linkage. This is a limitation of linking postal and census geography. Two examples of multiple linkage are block face assignment and multiple points.
Block face assignment results in a single point location representing all households along an uninterrupted street segment. Dense block face assignments in urban areas follow the familiar grid pattern of streets and provide a useful geocoding tool. Users are advised that very long block faces may cross DA boundaries.
When multiple (i.e. non block-faced) postal codes are associated with individual DA polygons, their positions may also be based on FSA geographic centroids. These, in turn, may cause two or more postal codes to occupy the same coordinates.