| Number Contained in Indicator Variable | Description |
|---|---|
| A negative number (most commonly -1) | The number specifies, to the precompiler, that the associated input main variable should be treated as a null. Alternatively, it means the database returned a null for the associated column. |
| Zero | The number specifies, to the precompiler, that the associated input main variable is non-null or that a non-null value was successfully returned with no exception conditions applied. |
| A positive number | The number specifies, to the application, that truncation has occurred when returning a character or byte string to the associated main variable. This value represents the original length of the string before truncation. |
An indicator variable is defined as a 2-byte integer (smallint) or by a 4 digit signed zoned decimal.
In COBOL, the smallint form is declared as:
PIC S9(n) <comp>
where the value for n is 3 or 4 and <comp> is COMP-5 for MF COBOL and COMP for all other COBOL compilers.
The zoned decimal form is declared as:
PIC S9(4) <zoned decimal type>
where <zoned decimal type> is DISPLAY [SIGN {LEADING | TRAILING} [SEPARATE]]