Module custom, report.xml::

        <record model="ir.action.report" id="report_sale_custom">
            <field name="name">Sale</field>
            <field name="report_name">sale.sale</field>
            <field name="model">sale.sale</field>
            <field name="report">custom/sale.odt</field>
</field>
        </record>
        <record model="ir.action.keyword" id="report_sale_keyword">
            <field name="keyword">form_print</field>
            <field name="model">sale.sale,-1</field>
            <field name="action" ref="report_sale_custom"/>
        </record>