frequency list has some frequencies in bold?

Under interface, wlan1 (picking frequency tab) when I am picking what frequency to use some show up in bold text. Why is this? I have only noticed this since upgrading to 4.6. In this example I am seeing this in the 5ghz spectrum.

are you on superchannel? the bold ones are the legal channels for your country selection. if you are not using the bold ones you might be breaking the rules ; )

Not on superchannel and fortunately I am on a bold one. Thanks for the feed back.