... Institute, e-mail . ... Presentation . ... Special Astrophysical Observatory of the Russian Academy of Sciences (SAO RAS), Russia, balega@sao.ru . ... The (extra)Galactic diffuse interstellar medium: dust, molecules, and diffuse bands . ... Polarization in diffuse interstellar bands . ... Interstellar molecules and diffuse bands inside and outside our Galaxy . ... Institute of Astronomy, Moscow, Russia, wiebe@inasan.ru . Diffuse clouds as initial conditions for chemistry in starless cores . ...