function sets the occurrence label for a repeating item or group (i.e., the row label of a roster). This is especially useful when designing applications for mobile devices, as it allows you to specify the label that is displayed in the navigational case tree. If no item_name
is given, the function sets the occurrence label of the current field. The occurrence label is set to the string expression occurrence_label
The function returns a logical value of 1 (true) if the label was set successfully and 0 (false) if the occurrence for the item or group item does not exist.