+
+Note that if you don't specify bf(--backup-dir), (1) the
+bf(--omit-dir-times) option will be implied, and (2) if bf(--delete) is
+also in effect (without bf(--delete-excluded)), rsync will add a protect
+filter-rule for the backup suffix to the end of all your existing excludes
+(e.g. -f "P *~"). This will prevent previously backed-up files from being
+deleted. Note that if you are supplying your own filter rules, you may
+need to manually insert your own exclude/protect rule somewhere higher up
+in the list so that it has a high enough priority to be effective (e.g., if
+your rules specify a trailing inclusion/exclusion of '*', the auto-added
+rule would never be reached).