Each part and connection belongs to a family. Each item in TinkerCell belongs to a family. Shown here is a screenshot from Tinkercell with labels indicating the family that each part or connection belongs with. A family structure is important if a model should support ontologies or interact with databases. For example, the family information can be used by a Python script to screen for all the RBS parts being used in the model. The default visual representation can be changed by clicking the mouse right-button on the family icon. Each connection family has a different arrowhead, which can also be replaced.