With the design of reference models, an increase in the efficiency of information systems engineering is intended. This is expected to be achieved by reusing information models. Current research focuses mainly on configuration as one principle for reusing artefacts. According to this principle, all variants of a model are incorporated in the reference model facilitating adaptations by choices. In practice however, situations arise whereby various requirements to a model are unforeseen: Either results are inappropriate or costs of design are exploding. This paper introduces additional design principles that aim towards giving more flexibility to both the design and application of reference models.