Data compression can only be specified for an output file. Key compression can be specified for an output file or the rebuild of an existing file.
The /c option operates in a similar manner to the Compiler directives DATACOMPRESS and KEYCOMPRESS.
| Value | Description | 
|---|---|
| 0 | No data compression. | 
| 1 through 127 | Reserved. | 
| 128 through 255 | User-defined compression routines. | 
| Value | Description | 
|---|---|
| 0 | No key compression. | 
| 1 | Duplicates are compressed. | 
| 2 | Leading characters are compressed. | 
| 4 | Leading spaces are compressed. | 
| 8 | Trailing nulls are compressed. | 
-c:d1i6
specifies data compression routine 1, and index compression of leading characters and trailing spaces.
-c:i1
specifies key compression of duplicates only.