A CONTROL definition describes:
The CONTROL name
Whether the control is in a box, subpanel, or switch (CONTAINER_TYPE)
Which box, subpanel, or switch the control is in (CONTAINER_NAME)
The position of the CONTROL in the BOX (POSITION_HINTS).
Fields describing appearance and behavior of the control
CONTROL control_name { CONTAINER_TYPE BOX or SUBPANEL or SWITCH CONTAINER_NAME box_name or subpanel_name or switch_name TYPE control_type POSITION_HINTS position KEYWORD value KEYWORD value ... }