das Auftreten

1. 1

   behavior, conduct, demeanor, manner — a person's outward bearing or way of behaving towards others

2. 2

   occurrence (the occurring (of something)); incidence, outbreak

3. 3

   appearance, performance — instance of playing, or acting, of performing or participating in a public event (as an actor or artist)

Forms in lighter type are derived by the standard declension rules from the nominative, genitive and plural.