trytond-stock_location_history_state/message.xml

<?xml version="1.0"?>
<!-- The COPYRIGHT file at the top level of this repository contains the full
     copyright notices and license terms. -->
<tryton>
    <data grouped="1">
		<!-- stock.location.state -->
        <record model="ir.message" id="msg_stock_location_state_date_location_uniq">
            <field name="text">Combination of Date and Location must be unique.</field>
        </record>
    </data>
</tryton>