Creating NULL values from text files
It is possible to define a symbol, which when it occurs in a text file or an inline clause will be interpreted as a real NULL value. Use the following statement:
The symbol <sym> is to be interpreted as NULL. <sym> may be any string.
In order to reset this functionality to the default interpretation, use:
SET NULLINTERPRET=;
Information note The use of NULLINTERPRET
only affects data from text files and inline clauses.