res_users_view.xml

<?xml version="1.0" encoding="UTF-8"?>
<openerp>
    <data>
        <record id="view_users_form_gs1_barcode" model="ir.ui.view">
            <field name="name">res.users.form.gs1_barcode</field>
            <field name="model">res.users</field>
            <field name="type">form</field>
            <field name="inherit_id" ref="base.view_users_form" />
            <field name="arch" type="xml">
                <notebook position="inside">
                    <page string="GS1-128/GS1-Datamatrix barcodes">
                        <field name="gs1_barcode_prefix" />
                        <field name="gs1_barcode_separator" />
                    </page>
                </notebook>
            </field>
        </record>
    </data>
</openerp>