(Related to this question)
The FAA's ATC Orders section 2-1-4 lists a number of different flight types that should get priority handling when possible. The obvious candidates are all mentioned: emergency services, VIP flights, search and rescue etc. But these less obvious ones are listed too, what exactly are they?
Night Watch or Nightwatch is the program identifier for the USAF National Airborne Operations Center (NAOC), including at least certain Boeing E-4 flights.
NAOC (used in flight):
From JO 7110.65W:
The term “NAOC” will not be a part of the call sign but may be used when the aircraft is airborne to indicate a request for special handling.
From JO 7110.65W:
The code name “FLYNET” indicates that an aircraft is transporting a nuclear emergency team or a disaster control team to the location of a potential or actual nuclear accident or an accident involving chemical agents or hazardous materials. It is in the public interest that they reach their destination as rapidly as possible.
Classified. Related to operation Garden Plot. Presumably a callsign to be used by aircraft as part of that operation.
Term related to Special Air Mission flights in evacuation of government VIPs.
From JO 7110.65W:
The term “SCOOT” will not be part of the call sign but may be used when the aircraft is airborne to indicate a request for special handling.
Callsign for observation aircraft under the Treaty on Open Skies. The USAF aircraft used for this purpose is the OC-135.
From Wikipedia's Treaty on Open Skies:
Observation/Demonstration flights are conducted under rigid guidelines outlined in the Treaty of OPEN SKIES that govern sensor usage, maximum flight distances, altitudes and priorities.
