Customer Attribute - Use In Forms

Question

I've found tutorials discussing the creation of a new customer attribute, and they include this:

Mage::getSingleton('eav/config')
    ->getAttribute('customer_address', 'building_entry_code')
    ->setData('used_in_forms', array('adminhtml_customer_address'))
    ->save();

Two questions:

1. Where does this value get stored in the database?
2. Is the customer module the only one that uses this, or are there possible values for other modules like Sales (order attributes.)

Answer 1

This information gets stored in the table customer_form_attribute. This table contains the key to the form and the attribute_id.

It is only used with customer attribute and has the following forms as options.

1. adminhtml_checkout
2. adminhtml_customer
3. adminhtml_customer_address
4. checkout_register
5. customer_account_create
6. customer_account_edit
7. customer_address_edit
8. customer_register_address