\twocolwidtha{5cm}
\begin{twocollist}\itemsep=0pt
\twocolitem{\windowstyle{wxRB\_GROUP}}{Marks the beginning of a new group of radio buttons.}
+\twocolitem{\windowstyle{wxRB\_SINGLE}}{If your radio buttons are not
+consecutive siblings, they cannot form a group under Windows and you should use
+this style to indicate that each of them is handled individually.}
\end{twocollist}
See also \helpref{window styles overview}{windowstyles}.