[whpalmer4]

Yes, it matches against existing projects and contexts only, just as if you typed that same string in the project or context column in the Inbox. If there isn't a match, that field is left empty, and if there is neither a project nor a context, it ends up in the Inbox. Depending on your preferences for "Clean Up Inbox items which have", it's possible that if you have one of the less restrictive choices set, and you only match one of project or context, that your action will be refiled without the other (in the project with no context set, or in the default single action list with the context set).