Mechanism of simultaneous non-sequential four-neutron (4n) emission (or
`true' 4n-decay) has been considered in phenomenological five-body approach.
This approach is analogous to the model of the direct decay to the continuum
often applied to 2n- and 2p-decays. It is demonstrated that 4n-decay
fragments should have specific energy and angular correlations reflecting
strong spatial correlations of `valence' nucleons orbiting in their
4n-precursors. Due to the Pauli exclusion principle, the valence neutrons are
pushed to the symmetry-allowed configurations in the 4n-precursor structure,
which causes a `Pauli focusing' effect. Prospects of the observation of the
Pauli focusing have been considered for the 4n-precursors 7H and 28O.
Fingerprints of their nuclear structure or/and decay dynamics are predicted