  We propose a classification scheme for the circumnuclear medium of AGNs based
on their location in the A_V - N_H plane (related to dust absorption and gas
absorption, respectively). We present evidence that the A_V/N_H ratio is often
lower than the Galactic value. This is shown by the broad line ratios of a
sample of intermediate Seyferts, and by the optical/X-ray ratio of line
selected (as opposed to color selected) AGNs. We point out the implications for
the physical properties of the absorber. A complete classification would
require a third axis, related to the density of the absorber and/or its
distance from the AGN.
