  Exact cancellation of quantum amplitudes in multiphoton interferences with
Fock states at input, the so-called suppression or zero transmission laws
generalizing the Hong-Ou-Mandel dip, are useful tool in quantum information and
computation. It was recently suggested that all bosonic suppression laws follow
from a common permutation symmetry in the input quantum state and the unitary
matrix of interferometer. By using the recurrence relations for interference of
Fock states, we find a wealth of suppression laws on the beamsplitter and
tritter which are not explained by the permutation symmetry principle. Our
results reveal that in interference with Fock states on unitary multiports
there are whole families of suppression laws for arbitrary total number of
bosons even on asymmetric unitary multiports, beyond the previously formulated
permutation symmetry principle.
