 Bokulich (2008, and 2009 [Other Internet Resources]) has argued that interpreting the correspondence principle in terms of the selection rule not only illuminates Bohr’s claim that it explains the capriciousness of the spectral lines, but also his claim that the correspondence principle is a law of quantum theory. Indeed, the correspondence that he refers to as a “law” is the selection rule correspondence, which holds also for small quantum numbers, not just in the classical limit. It is a law because it is a universal (i.e., applying to all \(n)\) restriction on the allowed quantum transitions. To understand why it is a law of quantum theory (as opposed to a law of classical electrodynamics) it is helpful to consider Bohr’s following remarks: