More comments.

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@25507 a592a061-630c-0410-9148-cb99ea01b6c8

src/LayoutFile.h

@@ -45,8 +45,18 @@ private:
 };
 
 /// This class amounts to little more than a `strong typedef'.
+/// 
 /// A LayoutFile represents the layout information that is 
 /// contained in a *.layout file.
+/// 
+/// 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, boost::noncopyable {
 public:
 	/// check whether the TeX class is available

src/TextClass.h

@@ -290,11 +290,17 @@ private:
 
 /// A DocumentClass represents the layout information associated with a
 /// Buffer. It is based upon a LayoutFile, but may be modified by loading
-/// various Modules. It is thus a dynamic object, as opposed to LayoutFile's
-/// which are pretty much static. 
-///
+/// various Modules. 
+/// 
+/// In that regard, DocumentClass objects are "dynamic". But this is really
+/// an illusion, since DocumentClass objects are not (currently) changed
+/// when, say, a new Module is loaded. Rather, the old DocumentClass is
+/// discarded---actually, it's kept around in case something on the cut
+/// stack needs it---and a new one is created from scratch. 
+/// 
 /// In the main LyX code, DocumentClass objects are created only by
 /// DocumentClassBundle, for which see below.
+/// 
 class DocumentClass : public TextClass, boost::noncopyable {
 public:
 	///