The vertical bar at left and the continuous extension of the horizontal bar off to the top left indicate a parcel post roller cancel (a post-cancel) typically consisting of 5 town names around the perimeter of the roller. For some reason the bottom bar did not imprint or was absent.
Box cancels (Berne and West Baden) will tend to have larger letters than a typical precancel and extend wider than 1 stamp, also the bars will be farther apart than typical. The parcel rollers (Indianapolis) will often have horizontal bars with spacing more closely resembling a precancel, but the vertical bars are a give away. When struck square on a stamp, both can be tricky - especially with a short town name.