the screen. Again, there are generally few limits, but the most common
hierarchy is given in Figure \ref{fig:managership}. Note that sometimes
the parent and manager are the same object and not all regions may have
-a manager, but all have a parent--a screen if not anything else.
+a manager, but all non-screen regions have a parent---a screen if not
+anything else.
\subsubsection{Manager--managed relations}