tryton/modules/purchase/view/party_form.xml

<?xml version="1.0"?>
<!-- This file is part of Tryton.  The COPYRIGHT file at the top level of
this repository contains the full copyright notices and license terms. -->
<data>
    <xpath expr="//group[@id='links']" position="inside">
        <link icon="tryton-purchase" name="purchase.act_purchase_relate" empty="hide"/>
        <link icon="tryton-purchase" name="purchase.act_purchase_line_relate" empty="hide"/>
    </xpath>
    <xpath expr="/form/notebook/page[@id='general']" position="after">
        <page string="Supplier" id="supplier">
            <label name="customer_code"/>
            <field name="customer_code"/>
            <newline/>

            <label name="supplier_lead_time"/>
            <field name="supplier_lead_time"/>
            <label name="supplier_currency"/>
            <field name="supplier_currency"/>
        </page>
    </xpath>
</data>