If you look at the $R Jun-10 currency future, that statement would mean selling the contract at the highest Rand value you can and then later buying it at the lowest Rand value you can. That is how I would understand it. But sometimes it confuses me as well, because you don't know if it means you should open a new position or close an existing position!
If you are trading the ZAR/USD future, you are trading the relationship between the two. If you expect the rand to go up then you have the option of either buying ZAR or selling USD. It is the same thing! If you expect the rand to go down you can sell the ZAR or buy USD, again the same thing. It depends on whether you have access to ZAR/USD or USD/ZAR. Hope this makes sense.