Yes, it means you can only enter once, once you have entered on that visa if you leve you would need to apply for new visa. You can apply at your local immigration office for a re-entry permit.
I know its not visa related.....however many people on this page will be business owners and may already be doing this so they may be able to shed some light on something that is very confusing!! I'm sorry if its not allowed on here....but there doesn't seem to be a group for this kind of question!!