By developing a custom module, I extended partner model and view with some more fields. Inside view, I added a notebook page containing all these additional fields. So far, so good. What I still need to do is to change location of partner.ref field. I do not want it to be shown at sale & purchase notebook page, but on my own page.

I tried the example code of the OEP documentation by putting it within the section of my new notebook page (see code section below). This shows partner.ref at the location I want, but it is not deleted from its old location and values entered to new location are not persisted. That means, this way it is completely useless. Can you tell me, what I did wrong?

<page string="Internal Notes" position="before">

<page string="Additional Information" colspan="4">

        <group>
            <!--additional fields -->
              <field name="ref" position="replace" select="1"/>
               <field name="cust_category" label="Customer category" select="1" position="before">
                    <field name="ref"/>
               </field>`