(if (= severity 0)
t
:no-dynamic-definition)
If this is nil , the CLOS package is smashed. It can no longer be used by the application.
If it is :no-dynamic-definition , then the functions for dynamic class and method definition are deleted -- functions like defmethod , defclass and so on, but the rest of the CLOS package is retained.
If it is t , nothing is smashed or deleted.
Note: MOP programmers should note that the direct-slots and direct-methods of all classes are emptied during delivery. To prevent this, set :keep-clos to :no-empty (which keeps dynamic definition) or :no-empty-no-dd (which does not keep dynamic definition).