mysql> SELECT DISTINCT(form_code) FROM customer_form_attribute;
+----------------------------+
| form_code |
+----------------------------+
| adminhtml_checkout |
| adminhtml_customer |
| adminhtml_customer_address |
| checkout_register |
| customer_account_create |
| customer_account_edit |
| customer_address_edit |
| customer_register_address |
+----------------------------+
8 rows in set (0.00 sec)