Zend certified PHP/Magento developer

filter_text column of magento_salesrule_filter table

I would like to know why whenever a new cart price rule is created it is incorporated into the magento_salesrule_filter table with the column filter_text = ‘true’ and what is this attribute for or what does it impact? I noticed that even when a coupon or cart rule is disabled, even so the filter_text follows as ‘true’.