This is a method on the generic function class-direct-subclasses.

For instances of standard-class, funcallable-standard-class, and forward-referenced-class, this methods returns a value which is maintained by add-direct-subclass (class class) and remove-direct-subclass (class class). This method can be overridden only if those methods are overridden as well.

For instances of built-in-class, This method returns a value derived from the information in the table showing the class inheritance structure, except that implementation-specific modifications are permitted as described in section ``Implementation and User Specialization.''