Fire Tone Out
From The RadioReference Wiki
Fire-Tone Out Operation allows the scanner to operate in a standby mode and respond to fire tone-outs, a system comprised of standardized two-tone sequential paging, short one-tone paging, and long group tone paging. You can save up to 10 settings. When you select a setting in standby mode, the scanner also monitors for any other setting that uses the same transmit frequency, modulation, and attenuation settings.
See The Unofficial Fire Tone Out Tutorial & Guide.
- Software known to decode Fire Tone outs