-a remote shell transport. If -e or --rsh are not specified or are set to
-the default "rsh", this defaults to blocking IO, otherwise it defaults to
-non-blocking IO. You may find the --blocking-io option is needed for some
-remote shells that can't handle non-blocking IO. (Note that ssh prefers
-non-blocking IO.)
+a remote shell transport. If the remote shell is either rsh or remsh,
+rsync defaults to using
+blocking IO, otherwise it defaults to using non-blocking IO. (Note that
+ssh prefers non-blocking IO.)