  Space-time localization diagrams ``unlock" subtle aspects of $\nu$
oscillations such as coherence and entanglement. Observability of propagation
decoherence in oscillating neutrino state is discussed. The sizes of WPs of
reactor and source neutrinos are estimated and it is shown that damping effect
due to decoherence is negligible. Among topics of interest are transition from
microscopic to macroscopic description of matter effects, oscillations in
non-linear generalization of Quantum Mechanics, influence of complex structure
of vacuum, in particular, possible presence of cosmic strings and domain walls
on oscillations, neutrino oscillations driven by the effective neutrino masses
generated via refraction on very light dark matter particles.
