Garmin G1000 Pilot's Manual page 157

The Airport Frequencies field uses the descriptions and abbreviations listed in Table 5-2:
190-00595-00 Rev. A
Communication
Frequencies Which
May Include Additional
Information
Approach
Arrival
Class B
Class C
CTA
Departure
TMA
Terminal
TRSA
Table 5-2 Frequency Descriptions and Abbreviations
Garmin G1000 Pilot's Guide for the Beechcraft A36/G36
Communication Frequencies
Without Additional
Information
ATIS
ASOS
AWOS
Center
Clearance
Gate
Control
Ground
Helicopter
Multicom
Pre-Taxi
Radar
Ramp
Other
Tower
Unicom
GPS NAVIGATION
Navigation
Frequencies
ILS
LOC
5-39