  This paper describes a practical model for the polarization of Be stars which
can be used to estimate roughly the physical parameters for optically thin
circumstellar envelopes from broadband UBVRI photopolarimetry data. Analysis of
long-term variability in terms of these parameters is a promising approach
toward understanding the Be phenomenon. An interesting result from fitting the
model to observations of eight Be stars is that all of them may have
geometrically thin disks, with opening half-angles on the order of ten degrees
or less. This contributes to the growing evidence that most Be disks are
geometrically thin.
