  QCD analysis of F_2^{\gamma}(x,Q^2) is revisited. It is emphasized that the
presence of the inhomogeneous term in the evolution equations for quark
distribution functions of the photon implies important difference in the way
factorization mechanism works in photon-hadron and photon-photon collisions as
compared to the hadronic ones. Moreover, a careful definitions of the very
concepts of the ``leading order'' and ``next-to-leading order'' QCD analysis of
F_2^{\gamma} are needed in order to separate genuine QCD effects from those of
pure QED origin. After presenting such definitions, I show that all existing
allegedly LO, as well as NLO analyses of F_2^{\gamma}(x,Q^2) are incomplete.
The source of this incompleteness of the conventional approach is traced back
to the lack of clear identification of QCD effects and to the misinterpretation
of the behaviour of q^{\gamma}(x,M) as a function of \alpha_s(M). Complete LO
and NLO QCD analyses of F_2^{\gamma}(x,Q^2) are shown to differ substantially
from the conventional ones. Whereas complete NLO analysis requires the
knowledge of two so far uncalculated quantities, a complete LO one is currently
possible, but compared to the conventional formulation requires the inclusion
of four known, but in the existing LO analyses unused quantities. The arguments
recently advanced in favour of the conventional approach are analyzed and shown
to contain a serious flaw. If corrected, they actually lends support to my
claim.
