This option is only relevant for the Embedded database.
For users who have embedded database tables that are still in 2.3 format, there is a conversion function that converts your tables to the DataFlex 3.0 database version. To convert your data, select Convert DF2.3 to 3.0 from the Database menu. This pops up the table-selection panel. Select the tables that you want to convert, then press the Convert to 3.0 button.