Map Test, or Command T, will redisplay an active map window giving you a self-test in which some note card titles are blanked.  The task is to determine the title, click under the note card, type in the correct term, and hit return.  If you are correct, the term will remain.  An incorrect response will be deleted and you may try again.  The correctness of the term is based on an exact match, ignoring case, with the term you have already assigned to the card.  If you want the term for a card revealed, simply Option-click it.  If you want all of the missing terms revealed, select Map Test, or Command T, again.