+///
+/// No document- (that is, Buffer-) specific information should
+/// be placed in these objects. They are used as the basis for
+/// constructing DocumentClass objects, which are what represent
+/// the layout information associated with a Buffer. (This is also
+/// a subclass of TextClass, implemented in TextClass.{h,cpp}.)
+/// Buffer-specific information should therefore be placed in a
+/// DocumentClass object.
+///
+class LayoutFile : public TextClass {