When the specified time has arrived to display an event's alarm the Alarm dialog will be shown, listing the details of any upcoming events.  Any alarm sounds specified will also be played.  The Alarm dialog contains a list view of the events with due alarms, just like the list view on the main Remind-Me window.  To the left of each event is a check box.  Place a check in this box to "acknowledge" the event.  Acknowledging an event will prevent you from being notified again of the same occurrence of this event.  You will still be notified about any following occurrences of this event.  By not "acknowledging" the event Remind-Me will continue to remind you of the event each day until you do "acknowledge" it.

An example of how to use acknowledgments:  Let's say you have recorded Judy's birthday as an event, and she was born on June 27th, 1966.  Assume you have told Remind-Me to start notifying you 7 days in advance of her birthday, and today is June 20th, 2007 (just prior to her 41st birthday). Today, when you turn on your computer you see the alarm about her upcoming birthday.  Since you've already bought her a present and mailed it to her, you don't wish to be reminded about her birthday again this year.  In this case, place a check next to her name in the Alarm dialog box by clicking on the status box with your mouse.  You will not be reminded about her birthday again, until just prior to her 42nd birthday.

Another possible scenario:  Assume the same situation as above, but you haven't bought Judy a present yet.  Leave the box next to her name un-checked, and you will be reminded again tomorrow.  Remind-Me will continue to remind you of her birthday until you've acknowledged it.

Events may also be acknowledged or un-acknowledged from the main window.  By right clicking on an event in either the list view or on a calendar you may acknowledge an event, or un-acknowledge a previously acknowledged event.

Acknowledging an event also prevents the e-mail for a particular event occurrence from being generated.  Expanding on the first example above, assume you see the alarm on June 20th and have already sent Judy her present, but still want to send her a personalized e-mail with voice recording on the 27th, the day of her birthday.  You would have specified under the e-mail options for this event to send e-mail to her 0 days in advance.  Even though you have already sent Judy her present, you would not want to "acknowledge" this event until the 27th, when you would send her an e-mail message.  Remind-Me will continue to remind you of her birthday until you acknowledge the event on the 27th.