cashbook_bookcategory/view/category_form.xml

<?xml version="1.0"?>
<!-- This file is part of the cashbook-module from m-ds for Tryton.
The COPYRIGHT file at the top level of this repository contains the
full copyright notices and license terms. -->
<form col="2">
    <label name="name"/>
    <field name="name"/>

    <notebook colspan="2">
        <page string="General Information" id="general" col="4">
            <label name="parent"/>
            <field name="parent"/>
            <field name="childs" colspan="4"/>
        </page>
        <page string="Cashbooks" name="cashbooks" col="1">
            <field name="cashbooks"/>
        </page>
    </notebook>
    <field name="company" invisible="1"/>

</form>