I think what you need to put on it is "Hand Cancel". But from what I have heard on this site (I posted the same type of question a couple of months ago), the post office doesn't always pay attention to that. I have heard that sometimes it helps if you hand deliver the card to the post office (someone at the counter) and make sure they know that it is "Hand Cancel".
This is the link to the question I asked a while ago (hopefully I did this right):
Forums at Splitcoaststampers
Hope this helps.