  It is known that the Field-Induced Spin-Density-Wave (FISDW) phases are
experimentally observed in the quasi-one-dimensional (Q1D) organic conductors
with chemical formula (TMTSF)$_2$X (X=PF$_6$, ClO$_4$, etc.) and some others in
moderate magnetic fields. From a theoretical point of view, they appear as a
result of "one-dimensionalization" of the Q1D electron spectra due to the
orbital electron effect in a magnetic field. We predict that the novel FISDW
phases with different physical meaning have to appear in inclined high magnetic
fields in Q1D conductors as a result of combination of the spin-splitting and
orbital electron effects. We suggest performing the corresponding experiments
in the (TMTSF)$_2$X materials.
