--write-devices write to devices as files (implies --inplace)
--dry-run, -n perform a trial run with no changes made
--whole-file, -W copy files whole (w/o delta-xfer algorithm)
---checksum-choice=STR choose the checksum algorithms (aka --cc)
+--checksum-choice=STR choose the checksum algorithm (aka --cc)
--one-file-system, -x don't cross filesystem boundaries
--block-size=SIZE, -B force a fixed checksum block-size
--rsh=COMMAND, -e specify the remote shell to use