diff --git a/unix/x0vncserver/Geometry.h b/unix/x0vncserver/Geometry.h
index 48ba228..3e5f23b 100644
--- a/unix/x0vncserver/Geometry.h
+++ b/unix/x0vncserver/Geometry.h
@@ -41,6 +41,8 @@
   const Rect& getRect() const { return m_rect; }
 
 protected:
+  // Parse a string, extract size and coordinates,
+  // and return that rectangle clipped to m_rect.
   Rect parseString(const char *arg) const;
 
   static StringParameter m_geometryParam;