From The RadioReference Wiki

Applies to: BCD436HP, BCD536HP, SDS100, SDS200

  • AVOID via Front Keypad or Menu
    • Temporary Avoid lets you quickly silence unwanted Systems, Departments, Channels, or search frequencies while allowing you to restore Avoids by cycling power.
    • Permanent Avoid lets you lockout anything unwanted by a quick double press
    • Ability to Clear All Avoids quickly and easily in a few MENU presses

See these Easier to Read manuals for more information