Those are "Service Search" systems, you can't remove those. Just don't scan them.
If they are scanning with your other systems you have 'Search with Scan' set. Go into Menu, scroll to 'Search for...' and press E/yes (or press down on knob), scroll to 'Edit' and press E/yes, Scroll to 'Service' and press E/yes (select the service) and press E/yes, scroll to 'Search with Scan' and press E/yes, scroll to 'Lockout', select Lockout and press E/yes.
The scanner also has three search keys that you can assign to a special search range. The search keys are set to number keys 1, 2, and 3. This allows you to start a service, custom, Tone-Out, or Band Scope search without having to go into the menus.
To program a Search Key, press Menu. Scroll to 'Search for...' and press E/yes.
Scroll to 'Set Search Key' and press E/yes.
At 'Select Key No.' scroll to 'Search Key 1-3' and press E/yes.
Scroll to any service search, custom search, 'Tone-Out', or 'Band Scope' and press E/yes.
Repeat for any other search keys you want to program. Press L/O to exit. The default settings for the BCD396XT are:
SRCH 1: Custom 1
SRCH 2: Public Safety
SRCH 3: Band Scope Mode