- "On platforms supporting it (the X11 based platforms), selects the
-so called PRIMARY SELECTION as the clipboard as opposed to the
-normal clipboard, if primary is True.", "");
+ "On platforms supporting it (the X11 based platforms), selects the so
+called PRIMARY SELECTION as the clipboard as opposed to the normal
+clipboard, if primary is True. On other platforms all clipboard
+operations fail when using the primary selection. This allows code
+supporting the primary selection to be written without ill effects on
+the other platforms.", "");