Abbreviation Conditions COMMS

When it comes to abbreviation of callsigns firstly check what type of callsign is being abbreviated - as with so much of comms, the rules are different for ground and air callsigns. With air callsigns, the rule is simple - you can abbreviate in the air only after air traffic have done so first. For ground callsigns (and bear in mind, an "aeronautical station" is a ground callsign) then you can abbreviate once communications are established and it will not cause confusion to do so. Ground callsigns can be abbreviated to either the location ("London") or the service being provided ("Tower") with the latter usually being better in practice.