odoo-contact-addons/partner_contact_phones2/views/res_partner.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>

  <record id="view_partner_simple_form_inherit_fax" model="ir.ui.view">
    <field name="name">res.partner.view.form.simple.inherit</field>
    <field name="model">res.partner</field>
    <field name="inherit_id" ref="base.view_partner_simple_form" />
    <field name="priority">18</field>
    <field name="arch" type="xml">
      <field name="phone" position="after">
        <field name="phone2" widget="phone" />
      </field>
      <field name="mobile" position="after">
        <field name="mobile2" widget="phone" />
        <field name="fax" position="move" />
      </field>
      <field name="fax" position="attributes">
        <attribute name="placeholder" value="" />
      </field>
    </field>
  </record>

  <record id="view_partner_form_inherit_base" model="ir.ui.view">
    <field name="name">res.partner.view.form.inherit</field>
    <field name="model">res.partner</field>
    <field name="inherit_id" ref="base.view_partner_form" />
    <field name="priority">18</field>
    <field name="arch" type="xml">
      <field name="phone" position="after">
        <field name="phone2" widget="phone" />
      </field>
      <field name="mobile" position="after">
        <field name="mobile2" widget="phone" />
      </field>
      <label for="email" position="before">
        <field name="fax" placeholder="" position="move" />
      </label>
      <field name="fax" position="attributes">
        <attribute name="placeholder" value="" />
      </field>
      <xpath expr="//field[@name='child_ids']/form//field[@name='phone']" position="after">
        <field name="phone2" widget="phone" />
      </xpath>
      <xpath expr="//field[@name='child_ids']/form//field[@name='mobile']" position="after">
        <field name="mobile2" widget="phone" />
      </xpath>
      <xpath expr="//field[@name='child_ids']/form//field[@name='fax']" position="attributes">
        <attribute name="placeholder" value="" />
      </xpath>
    </field>
  </record>

</odoo>