  After reviewing a connection between quantum chromodynamics and contituent
quark model pictures in the light-front quantization with some comparison and
contrast to the ordinary equal-time bridge a la Bogoliubov-Valatin
transformation, we discuss some newer development of the light-front quark
model phenomenology in exclusive processes including the embedded state. The
skewed parton distribution appears to be a good testing ground for our new
effective treatment of the light-front nonvalence contributions in timelike
exclusive processes.
