symbolic internal threads

Hi, I was wondering if it was possible that whenever I create a threaded hole, that symbolic threads are automatically added to it. Because I to 95% of my work on the CAM side I add a lot of chamfers to my parts and the little dashed line around a threaded hole becomes hard to see sometimes. Also, is the thread command able to create internal threads? I have only been able to make external thread like on a bolt. 

Thanks.