Does ListFind look for partial matches?

My problem is I am having issues with it not finding partial matches. For example, the URL I am using is index.cfm?var=update. The page aborts as it should because it found "update" but didn't find "update" in the goodParamValues list. If I do something like index.cfm?var=update_di it should still fail because "update_di" contains "update", but "update_di" isn't a value in the goodParamValues list.

What is a better way to go about this?