(1) In RPG, one or more fields that are compared from record to record to determine when the information in the fields changes. When the information changes, the control level indicator (L1 through L9) assigned to a control field is set on.
(2) In AFP Utilities, an input field on the screen view that is used to move the image area up, down, left, or right.
(3) In Application Development ToolSet, one or more specified fields that are compared to determine the record sequence in the output file.
(4) In data communications, a field within a frame that contains the commands, responses, sequence numbers, and poll or final bit for data link control.
(5) In MERVA Link, a field that is part of a MERVA message on the queue data set and of the message in the TOF. A control field is written to the TOF at nesting identifier 0. Messages in SWIFT format do not contain a control field.