-Classes may be given names
-from the set of upper case letters.
-Lower case letters and special characters
-are reserved for system use.
+Classes are named as a single letter or a word in {braces}.
+Class names beginning with lower case letters
+and special characters are reserved for system use.
+Classes defined in config files may be given names
+from the set of upper case letters for short names
+or beginning with an upper case letter for long names.