+dit(bf(-x, --one-file-system)) This tells rsync to avoid recursing into a
+directory that is the mount-point for another filesystem, including (as of
+2.6.7), "bind" mount-points. You can still copy the contents of multiple
+file systems if you include a source dir from each file system -- this just
+limits rsync's directory-recursion algorithm.
+
+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).