Thats not really all correct, wlmr.
There are a few steps to take, some of which wlmr touched on.
1) When the radio is programmed, at the very least, the "non-priority members" section must be set as "operator select". Also you can set "operator select" on priority channels.
2) Once you do so, you can adjust the scan list 3 different ways:
1. Set a side button. Press and hold that side button to put it into program mode.
2. Set one of your ABC switch positions to scan program.
3. If it is a model 2 / 3 set one of your menu options to "program".
3) Once you are in programming mode, there are couple of settings to remember
1. A "Z" is actually the scan symbol. (Its not really a Z, just looks like one.)
2. You can press "Sel" (select) to add a talkgroup to a list, or adjust its priority.
3. A solid dot next to the Z, means priority 1.
4. A blinking dot next to the Z is a priority 2.
5. "Del" removes it from the list.