+=head1 SCHEMA DESIGN
+
+RT uses a convention to denote the foreign key status in its tables.
+The rule of thumb is:
+
+=over 4
+
+=item When it references to another table, always use the table name
+
+For example, the C<Template> field in the C<Scrips> table refers to
+the C<Id> of the same-named C<Template> table.
+
+=item Otherwise, always use the C<Id> suffix
+
+For example, the C<ObjectId> field in the C<ACL> table can refer
+to any object, so it has the C<Id> suffix.
+
+=back