I would suggest this as an addition to the Creed, but it would probably endanger the Orthodox/Catholic relationship more than the filioque. Thanks to the Ironic Catholic who linked it from Orthometer.
Don Vincente: Erik, always remember the fifth mark of the Church.
Me: Fifth mark?? (Thinking that father had gone off into lala-land.)
Don Vincente: The Church is One, Holy, Catholic, Apostolic and funny.