The Default Value property, displayed in the Properties pane when a data item is selected, is used in write operations if the item is not represented by a column in an SQL INSERT statement.
This value is editable if you select the Edit default values option on the File tab of the Options pane.
Depending on the COBOL type, you can select from a list of figurative constants, or you can enter your own default appropriate to the data type. The value will be limited to the range of values that is valid for the underlying COBOL data type.