This flag applies only when INFLD is used in GUI mode (see type |G) and the field is implemented using a control type that has a drop-down option (e.g. date picker, combo box). In such a case, the drop-down display will be triggered automatically at the start of the field editing operation (as if the user had clicked on the drop-down button).
Note that this usage is often appropriate when the field is being called in response to a mouse click. One way to detect that within a centralized INFLD wrapper routine would be to check if the incoming value of exitcode matches the value associated with the current field (as defined in the hlpidx parameter).
