+Rsync will copy the directory at each encountered mount-point unless this
+option is repeated. Note, however, that the attributes of this mount-point
+directory are copied from those currently visible in the filesystem, not
+the inaccessible attributes of the underlying directory.
+
+This option does not affect the "collapsing" of symlinks that options such
+as bf(--copy-links) perform, irrespective of what filesystem the symlink's
+referent may be on.
+
+dit(bf(--existing, --ignore-non-existing)) This tells rsync to skip
+updating files that do not exist yet on the destination. If this option is
+combined with the bf(--ignore-existing) option, no files will be updated
+(which can be useful if all you want to do is to delete missing files).
+
+dit(bf(--ignore-existing)) This tells rsync to skip updating files that
+already exist on the destination. See also bf(--ignore-non-existing).