The inlays are made by punching holes in a piece of paper. I think what you're seeing is a case of "the hanging chad". The collectors in Florida will be familiar with this [g].

I'd consider it more a defect than a variety, since it is probably unique to a process variable on a particular chip. If you should find it on a lot of chips of this design, then I'd say it might be a result of a broken pin in the punch die; then it might be thought of as a variety.