# 1 Callsigns

1.1 Members connecting to the VATSIM network should use the following callsign naming convention for the ATC positions in VATCAR airspace: Three or four-letter ICAO/FAA code (for Airport or Facility), followed by the three-letter ATC callsign suffix (as applicable).

1.2 The following ATC callsign suffixes are authorized for use:

• _OBS – used by all members connecting as observers (LISTENING ONLY)
• _DEL – used by all members connecting as a Clearance Delivery controller
• _GND – used by all members connecting as a Ground controller
• _TWR – used by all members connecting as a Local/Tower controller
• _APP – used by all members connecting as an Approach controller
• _DEP – used by all members connecting as a Departure controller
• _CTR – used by all members connecting as an En Route/Center controller
• _FSS – used by all members connecting for oceanic sectors or the Caribbean Flight Service Station
• _SUP – used by VATSIM network supervisors only

1.3 Identification initials may also be used when connected to the VATSIM network, placed between the ICAO codes and callsign suffixes, to provide additional information. The following ID initials are authorized for use:

• _XX_ – signifying the operator’s initials when connecting as an observer
• _I_ – used by instructors while actively instructing on the network
• _M_ – used by mentors while actively mentoring on the network
• _L_ – used by students when solo endorsed to work a position on the network
• _S_ or _T_ – used by students working with an instructor/mentor on the network

1.4 VATCAR staff members logged on to VATSIM for an official operating capacity shall use their staff callsign and designated staff number: VATCAR[number]