L<FS::svc_external> - Externally tracked service class.
+L<FS::svc_pbx> - PBX service class
+
+L<FS::svc_cert> - Certificate service class
+
L<FS::inventory_class> - Inventory classes
L<FS::inventory_item> - Inventory items
L<FS::cust_main::Billing_Realtime> - Customer real-time billing class
+L<FS::cust_main::Packages> - Customer packages class
+
L<FS::cust_location> - Customer location class
L<FS::cust_main_Mixin> - Mixin class for records that contain fields from cust_main