This is a Special Mass that you will attend with your family or with a group. For example, you have a group with a special devotion (that's a "Votive Mass"), or your family would like to be present at a Special Mass for the anniversary of a loved one's death (that's a "Memorial Mass"), or you wish to give thanks to God on the occasion of your child's birthday, or other reasons. This Special Mass cannnot be scheduled at a time when there is already a regular parish Mass (see schedule here).