I have a list of the local ATC tower, ground, and local railroads. The airport has 2 mainline railroads on either side. So when I go to watch planes, I can use that list. I also have a list of the mobile frequencies for the P25 county wide system with ATC tower and ground. That comes in handy when there is snow removal activity at the airport so I can monitor the snow equipment and ATC since the snow removal is on the county wide. Easier than locking a bunch of lists out. I can't put conventional frequencies in the same list as a P25 system.