NLM Quiz no. 13 : Why Is This Inscription Written This Way? : The Answer

Can you guess why this inscription is written with some letters taller than the others? Please give your answer in the comments, and give if your Latin is up to it, a translation. To make this more interesting, please make your answer in the combox before reading the other comments.

(The image has been cropped at the bottom to hide a clue which might have made this too easy, but the inscription itself is complete.)

(The complete image; the date formed by the taller letters in the main body of the inscription appears on the lower left side in Roman numerals arranged in the normal way, MCMLXXXV, and on the lower right in Arabic numerals.)

The Answer: Congratulations to all those who figured out that the taller letters are all Roman numerals, which added up together, make the number 1985, the year in which Pope John Paul II visited the Cathedral of Our Lady in the city of Luxembourg. Kudos in particular to Roland de Chanson, who correctly noted that the inscription "cheats" by counting the first I of "Maiis" as a J, although it does not do so for the first I in "Ioannes". The Best Wildly Incorrect answer award goes to Albertus, for coming up with a date 7 years prior to the Pope's election. For Best Humorous Answer, we have a runner up, Inigo (it will be hard to follow up your winning entry in Quiz no. 12, good sir, but I look forward to your efforts,) but the winner is Josiah Ross, who suggested that someone's pinky kept accidentally hitting the caps button.

The high altar of the Cathedral.