For most people, the lower sign is probably redundant. The one above it mentions some feats accomplished by this Sled, like flying the first three of nine sorties from the eastern US seaboard to the Middle East - and back - during the Yom Kippur War. These missions were flown out of Griffiss AFB, NY, and involved close to 11.5 hours of Blackbird air time, including over five hours above Mach 3.0.