-V, --version display version number
-1, --fast compress faster
-9, --best compress better
+ --rsyncable Make rsync-friendly archive
With no FILE, or when FILE is -, read standard input.
into the directory and compress all the files it finds there (or
decompress them in the case of @command{gunzip}).
+@item --rsyncable
+While compressing, synchronize the output occasionally based on the
+input. This can reduce the compression slightly in some cases, but
+means that the @code{rsync} program can take advantage of similarities
+in the uncompressed input when syncronizing two files compressed with
+this flag. @code{gunzip} cannot tell the difference between a
+compressed file created with this option, and one created without it.
+
+@item --rsyncable
+While compressing, synchronize the output occasionally based on
+the input. This increases size by less than 1 percent most
+cases, but means that the @command{rsync} program can much more efficiently
+synchronize files compressed with this flag. @command{gunzip}
+cannot tell the difference between a compressed file created
+with this option, and one created without it.
+
@item --suffix @var{suf}
@itemx -S @var{suf}
Use suffix @var{suf} instead of @samp{.gz}. Any suffix can be