When you create and inherit objects in some custom or specific modules, it is better to inherit (than to replace) from an existing view to add/modify/delete some fields and preserve the others.

Example:

<record model="ir.ui.view" id="view_partner_form">
    <field name="name">res.partner.form.inherit</field>
    <field name="model">res.partner</field>
    <field name="inherit_id" ref="base.view_partner_form"/>
    <field name="arch" type="xml">
        <notebook position="inside">
            <page string="Relations">
                <field name="relation_ids" colspan="4" nolabel="1"/>
            </page>
        </notebook>
    </field>
</record>

<record model="ir.ui.view" id="view_partner_form">
    <field name="name">res.partner.form.inherit</field>
    <field name="model">res.partner</field>
    <field name="inherit_id" ref="base.view_partner_form"/>
    <field name="arch" type="xml">
        <notebook position="inside">
            <page string="Relations">
                <field name="relation_ids" colspan="4" nolabel="1"/>
            </page>
        </notebook>
    </field>
</record>

The inheritance engine will parse the existing view and search for the root nodes of

<field name="arch" type="xml">

<field name="arch" type="xml">

You can use these values in the position attribute:

• inside (default): your values will be appended inside the tag
• after: add the content after the tag
• before: add the content before the tag
• replace: replace the content of the tag.

Replacing Content

<record model="ir.ui.view" id="view_partner_form1">
    <field name="name">res.partner.form.inherit1</field>
    <field name="model">res.partner</field>
    <field name="inherit_id" ref="base.view_partner_form"/>
    <field name="arch" type="xml">
        <page string="Extra Info" position="replace">
            <field name="relation_ids" colspan="4" nolabel="1"/>
        </page>
    </field>
</record>

<record model="ir.ui.view" id="view_partner_form1">
    <field name="name">res.partner.form.inherit1</field>
    <field name="model">res.partner</field>
    <field name="inherit_id" ref="base.view_partner_form"/>
    <field name="arch" type="xml">
        <page string="Extra Info" position="replace">
            <field name="relation_ids" colspan="4" nolabel="1"/>
        </page>
    </field>
</record>

The parent and the inherited views are correctly updated with --update=all argument like any other views.

Deleting Content

To delete a field from a form, an empty element with position="replace" attribute is used. Example:

<record model="ir.ui.view" id="view_partner_form2">
    <field name="name">res.partner.form.inherit2</field>
    <field name="model">res.partner</field>
    <field name="inherit_id" ref="base.view_partner_form"/>
    <field name="arch" type="xml">
        <field name="lang" position="replace"/>
    </field>
</record>

<record model="ir.ui.view" id="view_partner_form2">
    <field name="name">res.partner.form.inherit2</field>
    <field name="model">res.partner</field>
    <field name="inherit_id" ref="base.view_partner_form"/>
    <field name="arch" type="xml">
        <field name="lang" position="replace"/>
    </field>
</record>

To add a field into a form before the specified tag use position="before" attribute.

<record model="ir.ui.view" id="view_partner_form3">
    <field name="name">res.partner.form.inherit3</field>
    <field name="model">res.partner</field>
    <field name="inherit_id" ref="base.view_partner_form"/>
    <field name="arch" type="xml">
        <field name="lang" position="before">
            <field name="relation_ids"/>
        </field>
    </field>
</record>

Will add relation_ids field before the lang field.

<record model="ir.ui.view" id="view_partner_form3">
    <field name="name">res.partner.form.inherit3</field>
    <field name="model">res.partner</field>
    <field name="inherit_id" ref="base.view_partner_form"/>
    <field name="arch" type="xml">
        <field name="lang" position="before">
            <field name="relation_ids"/>
        </field>
    </field>
</record>

Will add relation_ids field before the lang field.

<record model="ir.ui.view" id="view_partner_form4">
    <field name="name">res.partner.form.inherit4</field>
    <field name="model">res.partner</field>
    <field name="inherit_id" ref="base.view_partner_form"/>
    <field name="arch" type="xml">
        <field name="lang" position="after">
            <field name="relation_ids"/>
        </field>
    </field>
</record>

Will add relation_ids field after the lang field.

<record model="ir.ui.view" id="view_partner_form4">
    <field name="name">res.partner.form.inherit4</field>
    <field name="model">res.partner</field>
    <field name="inherit_id" ref="base.view_partner_form"/>
    <field name="arch" type="xml">
        <field name="lang" position="after">
            <field name="relation_ids"/>
        </field>
    </field>
</record>

Will add relation_ids field after the lang field.

To make changes in more than one location, wrap the fields in a data element.

<record model="ir.ui.view" id="view_partner_form5">
    <field name="name">res.partner.form.inherit5</field>
    <field name="model">res.partner</field>
    <field name="inherit_id" ref="base.view_partner_form"/>
    <field name="arch" type="xml">
        <data>
            <field name="lang" position="replace"/>
            <field name="website" position="after">
                <field name="lang"/>
            </field>
        </data>
    </field>
</record>

<record model="ir.ui.view" id="view_partner_form5">
    <field name="name">res.partner.form.inherit5</field>
    <field name="model">res.partner</field>
    <field name="inherit_id" ref="base.view_partner_form"/>
    <field name="arch" type="xml">
        <data>
            <field name="lang" position="replace"/>
            <field name="website" position="after">
                <field name="lang"/>
            </field>
        </data>
    </field>
</record>

XPath Element

<record model="ir.ui.view" id="view_partner_form6">
    <field name="name">res.partner.form.inherit6</field>
    <field name="model">res.partner</field>
    <field name="inherit_id" ref="base.view_partner_form"/>
    <field name="arch" type="xml">
        <data>
            <xpath
                expr="//field[@name='address']/form/field[@name='email']"
                position="after">
                <field name="age"/>
            </xpath>
            <xpath
                expr="//field[@name='address']/tree/field[@name='email']"
                position="after">
                <field name="age"/>
            </xpath>
        </data>
    </field>
</record>

Will add the age field after the email field in both the form and tree view of the address list.

<record model="ir.ui.view" id="view_partner_form6">
    <field name="name">res.partner.form.inherit6</field>
    <field name="model">res.partner</field>
    <field name="inherit_id" ref="base.view_partner_form"/>
    <field name="arch" type="xml">
        <data>
            <xpath
                expr="//field[@name='address']/form/field[@name='email']"
                position="after">
                <field name="age"/>
            </xpath>
            <xpath
                expr="//field[@name='address']/tree/field[@name='email']"
                position="after">
                <field name="age"/>
            </xpath>
        </data>
    </field>
</record>

Will add the age field after the email field in both the form and tree view of the address list.