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.
... verb is also has a grammatical voice: either active, passive or middle. (Middle indicates actions done to something other than the speaker for the speaker's own benefit. ...