It is a selection rule that rigorously applies to atoms, and to molecules that are centrosymmetric, i.e. with an inversion centre.
The Laporte rule is most commonly discussed in the context of the electronic spectroscopy of transition metal complexes.
[5] The Laporte rule helps explain the intense colors often observed for the tetrahedral complexes.
The tetrahedral point group lacks the inversion operation, so the Laporte rule does not apply.
[6] Illustrative of this effect are the disparate extinction coefficients for octahedral vs tetrahedral complexes of Co(II).
Illustrative of this combined effect is the faintness of even concentrated solutions of octahedral Mn(II) and Fe(III) complexes.