This ReferenceTypecan be used to expose the relation between a component to other components, that the component needs in order to work. In contrast to the Requires ReferenceType, this non-hierarchical ReferenceTypeallows loops, e.g. both components need each other in order to work. In that case, there would be two References, the first one pointing from one component to the other, and the second one vice versa. For example, a fan in a PC needs the power supply in order to work and the power supply needs the cooling from the fan, that it is not overheating. An example of a non-looping usage is that a robot utilizes a vision system in order to get the position where to grab something.