Illustration of the three formation pathways that a system with a new sink ID is classified into: top: if a sink is formed and is gravitationally bound to another sink or stellar system at birth (marked with a solid line), this is bound core fragmentation, middle: if a sink is formed and is gravitationally unbound at birth, but later becomes bound to the sink or stellar system it was most bound to at birth (marked with a dashed line), this is unbound core fragmentation, and bottom: if a sink is formed and is gravitationally unbound at birth, and later becomes bound to a sink or stellar system that is different to the one it was most bound to at birth, this is dynamical capture.