Defined here is the data type of the global variable. If the data type is the alphanumeric type and defined with a length, the global variable is then generated with a length defined by GLONxxx (xxx=data type).
The length is mandatory if the data type indicated in the record is of the type internal alphanumeric, clob or blob and does not have a length entered.
On the other hand, the length is not entered where the data type is of an internal type other than alphanumeric, clob and blob.