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@@ -13,29 +13,34 @@ but on files of only a few MB plzip is no faster than lzip.
Plzip uses the lzip file format; the files produced by plzip are fully
compatible with lzip-1.4 or newer, and can be rescued with lziprecover.
-The lzip file format is designed for long-term data archiving and
-provides very safe integrity checking. The member trailer stores the
-32-bit CRC of the original data, the size of the original data and the
-size of the member. These values, together with the value remaining in
-the range decoder and the end-of-stream marker, provide a 4 factor
-integrity checking which guarantees that the decompressed version of the
-data is identical to the original. This guards against corruption of the
-compressed data, and against undetected bugs in plzip (hopefully very
-unlikely). The chances of data corruption going undetected are
-microscopic. Be aware, though, that the check occurs upon decompression,
-so it can only tell you that something is wrong. It can't help you
-recover the original uncompressed data.
-
-If you ever need to recover data from a damaged lzip file, try the
-lziprecover program. Lziprecover makes lzip files resistant to bit-flip
-(one of the most common forms of data corruption), and provides data
-recovery capabilities, including error-checked merging of damaged copies
-of a file.
+The lzip file format is designed for long-term data archiving, taking
+into account both data integrity and decoder availability:
+
+ * The lzip format provides very safe integrity checking and some data
+ recovery means. The lziprecover program can repair bit-flip errors
+ (one of the most common forms of data corruption) in lzip files,
+ and provides data recovery capabilities, including error-checked
+ merging of damaged copies of a file.
+
+ * The lzip format is as simple as possible (but not simpler). The
+ lzip manual provides the code of a simple decompressor along with a
+ detailed explanation of how it works, so that with the only help of
+ the lzip manual it would be possible for a digital archaeologist to
+ extract the data from a lzip file long after quantum computers
+ eventually render LZMA obsolete.
+
+ * Additionally lzip is copylefted, which guarantees that it will
+ remain free forever.
Plzip uses the same well-defined exit status values used by lzip and
bzip2, which makes it safer than compressors returning ambiguous warning
values (like gzip) when it is used as a back end for tar or zutils.
+Plzip will automatically use the smallest possible dictionary size for
+each file without exceeding the given limit. Keep in mind that the
+decompression memory requirement is affected at compression time by the
+choice of dictionary size limit.
+
When compressing, plzip replaces every file given in the command line
with a compressed version of itself, with the name "original_name.lz".
When decompressing, plzip attempts to guess the name for the decompressed