There are two ways to add a Trespass Warning to a names file. For beginners, learn how to do it from the wants screen. For experienced dispatchers, you probably know how to do it from the names screen. Learn both ways and decide which you like the best!
To turn off an existing flag: Change the Disposition to INA (Inactive) and change the time stamp in the Disp Date field to the date the flag is no longer effective.