  Given a bichromatic point set $P=\textbf{R} \cup \textbf{B}$ of red and blue
points, a separator is an object of a certain type that separates $\textbf{R}$
and $\textbf{B}$. We study the geometric separability problem when the
separator is a) rectangular annulus of fixed orientation b) rectangular annulus
of arbitrary orientation c) square annulus of fixed orientation d) orthogonal
convex polygon. In this paper, we give polynomial time algorithms to construct
separators of each of the above type that also optimizes a given parameter.
