<xpath expr="//field[@name='email']" position="attributes">
<attribute name="required">1</attribute>
</xpath>
+ <xpath expr="//notebook[@name='Volunteer activities']" position="before">
+ <group colspan="4">
+ <field name="welcome_email"/>
+ <field name="opt_out" string="I don't want to receive the newsletter (one per month approximatively)." help="Information about bikecoop, animation, association, …"/>
+ </group>
+ </xpath>
</field>
</record>
</data>