| Level | Code | Display | Definition |
| 1 | BZ | bzip |
bzip-2 compression format. See [http://www.bzip.org/] for more information.
|
| 1 | DF | deflate |
The deflate compressed data format as specified in RFC 1951 [http://www.ietf.org/rfc/rfc1951.txt].
|
| 1 | GZ | gzip |
A compressed data format that is compatible with the widely used GZIP utility as specified in RFC 1952 [http://www.ietf.org/rfc/rfc1952.txt] (uses the deflate algorithm).
|
| 1 | Z | compress |
Original UNIX compress algorithm and file format using the LZC algorithm (a variant of LZW). Patent encumbered and less efficient than deflate.
|
| 1 | Z7 | Z7 |
7z compression file format. See [http://www.7-zip.org/7z.html] for more information.
|
| 1 | ZL | zlib |
A compressed data format that also uses the deflate algorithm. Specified as RFC 1950 [http://www.ietf.org/rfc/rfc1952.txt]
|