rsync - Feb 2003 - rsync 2.5.6: --suffix option

The ChangeLog for rsync 2.5.6 mentions that the --suffix option has 
been added to control the suffix of files backed up to the 
--backup-dir.




Wasnt this already there in 2.5.5? 




In 2.5.5, if I do




--backup --backup-dir=mybackup --suffix=.old




it doesnt work? I thought it did.




Thanks