"The scanners also show another singal—on restricted band APA 5."
―Imperial officer[src]

Restricted Band APA 5 was a transmission frequency that could be picked up by Imperial scanners on the planet Yinchorr. It was known to be a frequency on which Rebels would send communications, and when a signal on this band was picked up by an officer loyal to Governor Marcellin Wessel, the governor knew that the signal could only be the emergency transmission by Leia Organa to her friends with the use of a emergency beacon.