Many visualization frameworks for ontologies in general and for concept expressions in particular are too faithful to the syntax of the languages in which those objects are represented (e.g., RDF, OWL, DL). Model outlines depart from this tradition in that they consist of diagrams characterizing the class of models of a given concept expression. We hope this semantically-oriented visualization strategy will allow users to obtain deeper insights about the meaning of such expressions, thereby preventing errors of design or of interpretation.