Aeronautical Operational Control (AOC) A group or the entirety of applications used for communication of an aircraft with its airline or service partner pendants on the ground. An AOC application was traditionally hosted on an ACARS MU or CMU.
Traditionally, AOC messages have been user defined, because they have only been exchanged between an airline and their own aircraft. Thus, controlling both ends, there was no need for standardization.
However, by introducing airframer defined ACARS messages (e.g. by the A380) and because of the increasing need to connect airline handling partners like fuel suppliers or de-icing companies, a need to standardize appeared. Recently, ARINC 633 was created to standardize these AOC messages.