WordNet
control operation
n. an operation that controls the recording or processing or transmission of interpretation of data; "a control operation started the data processing" [syn: control function]
Wikipedia
Control operation
In telecommunication, a control operation (control function) is an operation that affects the recording, processing, transmission, or interpretation of data.
Examples of control operations a font change, or a rewind; and transmitting an end-of-transmission (EOT) control character.