<odoo>

  <record id="id1" model="tutorial.example">

    <field name="related_id" ref="module.relatedid"/>

  </record>

</odoo>

It will call the ref method, and store the id of the record returned on the field related_id

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In python code, you can use the

env.ref(self, xml_id, raise_if_not_found=True)

​

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