U.S. Patent and Trademark Office building in Alexandria, Virginia. Photo: Diego M. Radzinschi/ALM

One little digit on an address form has caused one giant headache for a patent applicant.

Elan Pavlov's application for a patent on systems and methods for detecting fake news ran into trouble after his attorneys inadvertently gave their address as 33 N. Michigan Ave. in Chicago, rather than the correct 333 N. Michigan Ave.