Those are just locations of 800 MHz conventional mutual aid frequencies on a Seminole County radio.
Program these into your scanner and you can hear them
NPSAC (CTCSS tone of 156.7 on all frequencies)
ICALL - 851.0125
ITAC1 - 851.5125
ITAC2 - 852.0125
ITAC3 - 852.5125
ITAC4 - 853.0125
When used by SCFD for interop with Volusia (common), Lake (rare), and Brevard County (very rare) these are linked to TG's on the respective counties trunked systems.
Depending on where you live it may be easier or the reception is better to listen to the talkgroups on the linked systems.