pg_upgrade is not correct

The following documentation comment has been logged on the website:

Page: https://www.postgresql.org/docs/10/pgupgrade.html
Description:

If we use the following command to upgrade the standby server, then new
cluster will create by old_cluster which is not correct.
rsync --archive --delete --hard-links --size-only --no-inc-recursive
old_cluster new_cluster remote_dir
I used following command and this one is correct:
rsync --archive --delete --hard-links --size-only --no-inc-recursive
new_cluster old_cluster remote_dir 
So the only thing need to change is the place of old_cluster and new_cluster
in rsync command.