Use the AdditionalItemProperty subelement of the Item element to model this information.

Elements

Element	Description
`Invoice/InvoiceLine/Item/AdditionalItemProperty/Name`	The name of the attribute.
`Invoice/InvoiceLine/Item/AdditionalItemProperty/Value`	The value of the attribute.

Example

<Invoice>
    <!-- code omitted for clarity -->
    <cac:InvoiceLine>
        <!-- code omitted for clarity -->
        <cac:AdditionalItemProperty>
            <cbc:Name>Color</cbc:Name>
            <cbc:Value>Black</cbc:Value>
        </cac:AdditionalItemProperty>
        <!-- code omitted for clarity -->
    </cac:InvoiceLine>
</Invoice>