  We analyse a feature that is detectable at the differential phases of
high-resolution spectro-interferometry of Be stars. The origin of this feature
(dubbed CQE-PS, Central Quasi Emission Phase Signature) lies in the
differential absorption of photospheric radiation by the circumstellar disk,
which is spectroscopically detected as a CQE line profile in shell stars. This
phenomenon has great diagnostic potential for Be star disks, revealing
properties of these disks on the scale of a few stellar radii.
