Complex anaphors are nominal expressions that pick up sentential or longer antecedents referring to propositionally structured referents such as events and states. Concerning their textual function, complex anaphors do not only serve as a means of continuity but also effect the progression of the information flow in text, i.e. they are thematic and rhematic at the same time. The complexation process establishes the pre-mentioned referent as a unified discourse entity. On the basis of natural language corpus data, it is shown that complex anaphors have a central function in establishing coherence in texts. The paper distinguishes type shifting and non type shifting complexation processes where the former is subject to ontological based constraints. In order to show how ontological features are involved in disambiguation an example of ambiguous complex anaphora is discussed.