I am looking at the topic list in Elemental theme's Portfolio and Blog pages. I've noticed the topic nodes have an id included in their URLs.

For example, the URL of 'Homework' topic node on a Portfolio page looks like this: '/portfolio/topic/16/homework', with the id '16'. Is there a setting somewhere to remove this id from the URL so that the URL simply becomes '/portfolio/topic/homework'. I am unable to figure this out. I have Pretty URLs enabled.