Hi,

in sale order Invoice Address and Delivery Address is many2one field whith res.partner.

So you choose a partner and not an address type.

innovation in openerp 7 .

In order to avoid any confusion when dealing with contacts in OpenERP, we made some changes. The former structure (partner, address, contact) was slightly complex when dealing and communicating with individuals and not with companies (B2C situations).

We kept the same features, merged the two menu items (contacts and companies) and kept the same functionalities. As a result, now when you want to add any contact details, you can specify if it's a company or an individual by using a checkbox.

The biggest change is that, for example, when creating an invoice, you can now select a company or an individual, thus better facilitating B2C business processes. Every business document has been simplified with this change as you no longer have two fields on each document (Partner & Address) but just one field: the contact, which can be a person working at a company or directly a company.

for more details you can see OpenERP 7.0 Release Notes