fmon,
While I have listened to the above-mentioned searches, I was hesitant to use the Service Search FrL/O (F1) button because I didn't know how to Un-Lockout the frequencies. And because no frequencies were being selected/deselected "all/ALL" made no difference.
Taking your reply as a starting point I found in practice it appears "all" scans only the selected frequencies, while "ALL" scans every frequency (selected and deselected). Therefore, in "ALL" mode I not only scan every frequency, but having PAUSED the scan I can step through the channels to find the Locked-Out channel(s) and un-Lock them. In "all" mode the Locked-Out channels are invisible, the scanner just skips over the deselected channel.
Thank you for your reply. It has increased the utility of this scanner for me.
Tom