  We study the electronic structure of multilayer graphenes with a mixture of
Bernal and rhombohedral stacking and propose a general scheme to understand the
electronic band structure of an arbitrary configuration. The system can be
viewed as a series of finite Bernal graphite sections connected by stacking
faults. We find that the low-energy eigenstates are mostly localized in each
Bernal section, and, thus, the whole spectrum is well approximated by a
collection of the spectra of independent sections. The energy spectrum is
categorized into linear, quadratic and cubic bands corresponding to specific
eigenstates of Bernal sections. The ensemble-averaged spectrum exhibits a
number of characteristic discrete structures originating from finite Bernal
sections or their combinations likely to appear in a random configuration. In
the low-energy region, in particular, the spectrum is dominated by
frequently-appearing linear bands and quadratic bands with special band
velocities or curvatures. In the higher energy region, band edges frequently
appear at some particular energies, giving optical absorption edges at
corresponding characteristic photon frequencies.
