Zend certified PHP/Magento developer

How to add data to custom validation rule?

I would like to understand how to add additional data to custom validation rule. I noticed in Magento 2 core files something like the following:

        validator.addRule(
            'validate-customer-company',
            function (value, params, data) {
                return !(data.customer && data['is_company_user']
            },
            $.mage.__('Message')
    ...

Does anyone know where data parameter comes from? In my case value comes from input field, params is true and data is undefined. And the validation is added to company_form.xml like this:

<field name="fieldName">
    ...
    <settings>
        <validation>
            <rule name="custom_rule" xsi:type="boolean">true</rule>
        </validation>
    </settings>

Thanks!