If Data
View is displayed, double-click the variable name at the top of the
column in Data View or click the Variable View tab.
Click the button in the Missing cell for the variable that
you want to define.
Enter the values or range of values that represent missing data.
All string
values, including null or blank values, are considered to be valid
unless you explicitly define them as missing.
Missing
values for string variables cannot exceed eight bytes. (There is no
limit on the defined width of the string variable, but defined missing
values cannot exceed eight bytes.)
To define
null or blank values as missing for a string variable, enter a single
space in one of the fields under the Discrete missing values selection.