pos_notes/view/pos_order_view.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
    <data>

        <record id="pos_view_order_form" model="ir.ui.view">
            <field name="name">pos.order.form</field>
            <field name="model">pos.order</field>
            <field name="inherit_id" ref="point_of_sale.view_pos_order_tree"/>
            <field name="arch" type="xml">
                <field name="partner_id" position="after">
                    <field name="note"/>
                </field>
            </field>
        </record>

    </data>
</openerp>