Band Plans help restrict frequency finding for a device to a specific bandwidth (start frequency and stop frequency).
This process avoids interference caused by mics operating in the range of higher power IEM/IFB transmitters, even when the mic is capable of tuning to that range. It also restricts a device to a specific area of the spectrum to protect it from environmental noise or other issues.
The Protect feature of a Band Plan creates an exclusion for all other calculations that do not have the Band Plan selected. Candidates that fall within the protected band plan will not be used unless that Band Plan is selected.
Calculation
When calculating for frequencies with a Band Plan selected, Coord will only consider candidate frequencies within that Band Plan's Start and Stop frequency. When recalculating frequencies, the Band Plan which was used for that frequency's initial calculation will be used for the recalculation, keeping it contained to that Band Plan. Band Plans can be removed or a different one selected when recalculating a single frequency. When a Band Plan's Start or Stop is changed, these new values will be used during the recalculation process, but existing frequencies will not automatically be recalculated.