/**
* gdk_window_set_opaque_region:
* @window: a top-level or non-native #GdkWindow
- * @region: a region
+ * @region: (allow-none): a region, or %NULL
*
- * For optimizization purposes, compositing window managers may
+ * For optimisation purposes, compositing window managers may
* like to not draw obscured regions of windows, or turn off blending
* during for these regions. With RGB windows with no transparency,
* this is just the shape of the window, but with ARGB32 windows, the
*
* This function only works for toplevel windows.
*
- * GTK+ will automatically update this property automatically if
+ * GTK+ will update this property automatically if
* the @window background is opaque, as we know where the opaque regions
* are. If your window background is not opaque, please update this
* property in your #GtkWidget::style-updated handler.