To improve automobile safety, K.W. Muth Company developed a side view mirror that flashed when a driver activated the vehicle’s turn signal. Optical filters prevent the flashing turn signal from distracting the driver of that vehicle, but allow the turn signal to be seen by other drivers in the vehicle’s blind spot. The Trademark Office initially refused the application based on an assertion that the mark was so descriptive of the product that the mark was incapable of serving as a source identifier. Attorney Sokol submitted legal arguments and documents that persuaded the Office to withdraw this refusal, which resulted in the issuance of U.S. Registration No. 1,893,806.