Hidden SSIDs

Is it true that any hidden SSID within range of the imp will be reported with a blank SSID in the table returned by imp.scanwifinetworks()?

At the moment, I will attempt to connect to a hidden SSID regardless of whether I can see it or not. I wonder if I can trim the hidden ones from my search list if scanwifinetworks() returns only SSIDs with non-blank values.