  The structure of fractional fillings of higher Landau levels including spin
subbands is systematically derived for the first time. Using topology-type
commensurability arguments for 2D charged system in the presence of strong
quantizing magnetic field, a hierarchy of fillings in the higher Landau levels
for FQHE and for other correlated states is determined in perfect agreement
with the experimental observations. The relative paucity of fractional
structure in the higher Landau levels in contrast to the plethora of filling
factors for FQHE in the zeroth Landau level is explained. The filling fractions
with even denominators in consecutive LLs were also identified together with
the criterion for particle pairing.
