NULL's are used to represent unknown or missing data and SET NULL changes the display symbol for null. You can use up to four characters. If you set null to a blank space, R:BASE does not display rows composed entirely of nulls with the SELECT command. R:BASE stores the NULL setting with the database. When referring to null in commands it is preferential to use the NULL keyword as opposed to a given representation of NULL.

If you enter the following command, R:BASE displays a slash in the absence of data:

SET NULL /