[en] In our previous publications we discussed possible physical scenario standing behind rectangular–like structures in the fission fragments mass-correlation distributions from ²⁵²Cf(sf). The rectangle is bounded by the known magic nuclei such as ⁶⁸Ni, ⁸⁴Se and others. The fission events aggregated in the rectangle show extremely low total kinetic energies. Previously only decay mode with two Ni clusters in the exit channel was discussed. A more complete analysis is presented which gives additional arguments in favour of true quaternary fission of ²⁵²Cf (sf). (paper)