1. A resource that acts as a proxy for some subject; the topic map system's representation of that subject. The relationship between a topic and its subject is defined to be one of reification. Reification of a subject allows topic characteristics[?] to be assigned to the topic that reifies it.
... and 434 families residing in the town. The population density is 133.3/km² (345.1/mi²). There are 959 housing units at an average density of 83.8/km² ...