in some cases we could use country on Other for testing purpose of a link. In that case we want to select the frequencies among we can choose. So even if let on auto, such frequencies could be excluded, such as them could be select in client scan
I think he means a "blacklist / range" of channels, so even if country is set to "other", the auto-sense algorithm will not use certain channels, selected by the user.
as in:
Other country frequency range: 5950 - 6400
user selected range: 5950 - 5550
user select blacklist: 5350
in which case, even tohough the radio could operate in any of the channels from 5950 - 6400, the user is specifically calling for a clean channel in the lower-band, and i know 5350 is clean but there is a radar there, so i want to tell the radio to stay away of that frequency, even if auto-sense thinks it is a good clean channel.