Index: nsf.nxd
===================================================================
diff -u -r39306d4d36096f20dba3262638e2a87f04e90111 -rcc815189194d14214c6846ca33f39d74b4d8edc5
--- nsf.nxd	(.../nsf.nxd)	(revision 39306d4d36096f20dba3262638e2a87f04e90111)
+++ nsf.nxd	(.../nsf.nxd)	(revision cc815189194d14214c6846ca33f39d74b4d8edc5)
@@ -14,8 +14,6 @@
 # @version 1.0.0a
 # @namespace ::nsf
 
-
-#
 # @glossary metaclass
 #
 # A meta-class is a certain kind of <<@gls class>> that manages
@@ -24,8 +22,6 @@
 # @pretty_name Meta Class
 # @pretty_plural Meta Classes
 
-
-#
 # @glossary class
 #
 # A class is a certain kind of <<@gls object>> that is responsible for
@@ -40,7 +36,25 @@
 # @pretty_name Class
 # @pretty_plural Classes
 
+
+# @glossary baseclass
 #
+# A base class is the most general class (common root class) of an
+# object system.  All objects of an object system are direct or
+# indirect instances of the base class.
+#
+# @pretty_name Base Class
+# @pretty_plural Base Classes
+
+# @glossary basemetaclass
+#
+# A base meta class is the most general meta class of an object
+# system. All classes are direct or indirect instances of the base
+# meta class.
+#
+# @pretty_name Base Meta Class
+# @pretty_plural Base Meta Classes
+
 # @glossary object
 #
 # An object is the basic entity of an object system. Every object is
@@ -51,8 +65,6 @@
 #
 # @pretty_name Object
 # @pretty_plural Objects
-
-
 # @glossary alias
 #
 # An alias is an alternate name for some artefact. In NSF, the term