See also:

Conference Call
When two calls are in progress (one active and one on hold), press and hold the button until you hear a double beep indicating that the two calls have been joined into one conference call. ...

Control Setting Suggestions for Various Weather Conditions
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Supported Medium Formats (File Systems)
The medium formats supported by the radio are ISO 9660 Level 1 and Level 2 and includes the Joliet extension. When reading discs recorded using formats other than ISO 9660 Level 1 and Level 2, th ...