unless you’re sure of
              the choice in effect.  For example:

                  rsync ‐aiv ‐‐zc=zstd ‐‐zl=22 host:src/ dest/

              For  zlib  &  zlibx  compression the valid values are from 1 to 9
              with 6 being the default.  Specifying  --zl=0  turns  compression
              off, and specifying --zl=-1 chooses the default level of 6.

              For zstd compression the valid values are from -131072 to 22 with
              3 being the default. Specifying 0 chooses the default of 3.

              For  lz4  compression there are no levels, so the value is always
              0.

              If you specify a too‐large or  too‐small  value,  the  number  is
              silently  limited  to  a valid value.  This allows you to specify
              something like --zl=999999999 and be assured that you’ll  end  up
              with  the  maximum compression level no matter what algorithm was
              chosen.

              If you want to know the compression  level  that  is  in  effect,
              specify  --debug=nstr  to  see  the  "negotiated string" results.
              This will report something like "Client compress: zstd (level 3)"
              (along with the checksum choice in effect).

       --skip‐compress=LIST
              NOTE: no compression method currently supports per‐file  compres‐
              sion changes, so this option has no effect.

              Override  the  list  of  file suffixes that will be compressed as
              little as possible.  Rsync sets the compression level on  a  per‐
              file  basis based on the file’s suffix.  If the compression algo‐
              rithm has an "off" level, then no compression  occurs  for  those
              files.   Other  algorithms  that  support  changing the streaming
              level on‐the‐fly will have the level minimized to reduces the CPU
              usage as much as possible for a matching file.

              The LIST should be one or more file suffixes  (without  the  dot)
              separated by slashes (/).  You may specify an empty string to in‐
              dicate that no files should be skipped.

              Simple  character‐class  matching is supported: each must consist
              of a list of letters inside the square brackets (e.g. no  special
              classes,  such as "[:alpha:]", are supported, and ’-’ has no spe‐
              cial meaning).

              The characters asterisk (*) and question‐mark (?) have no special
              meaning.

              Here’s an example that specifies 6 suffixes to skip (since  1  of
              the 5 rules matches 2 suffixes):

                  ‐‐skip‐compress=gz/jpg/mp[34]/7z/bz2

              The  default file suffixes in the skip‐compress list in this ver‐
              sion of rsync are:

                  3g2 3gp 7z aac ace apk avi bz2 deb dmg ear f4v flac  flv  gpg
                  gz  iso jar jpeg jpg lrz lz lz4 lzma lzo m1a m1v m2a m2ts m2v
                  m4a m4b m4p m4r m4v mka mkv mov mp1 mp2 mp3 mp4 mpa mpeg  mpg
                  mpv  mts  odb odf odg odi odm odp ods odt oga ogg ogm ogv ogx
                  opus otg oth otp ots ott oxt png  qt  rar  rpm  rz  rzip  spx
                  squashfs  sxc  sxd sxg sxm sxw sz tbz tbz2 tgz tlz ts txz tzo
                  vob war webm webp xz z zip zst

              This list will be replaced by your --skip‐compress  list  in  all
              but  one  situation:  a  copy  from  a daemon rsync will add your
              skipped suffixes to its list of non‐compressing  files  (and  its
              list may be configured to a different default).

       --numeric‐ids
              With  this  option rsync will transfer numeric group and user IDs
              rather than using user and group names and mapping them  at  both
              ends.

              By default rsync will use the username and groupname to determine
              what  ownership