Since we're bringing up fun facts about Dutch capitalisation, when the first two letters are "IJ", which pronounced as a single letter (a vowel) in Dutch, then both are capitalised.
There are (a lot of) people who consider the 'ij' to be a single letter. When asked whether that means Dutch has 27 letters in the alphabet or the 'y' is not a Dutch letter, the discussion becomes very confused. Best explanation is probably that the 'ij' is a letter that's not in the alphabet, or it is, but shares the 25th spot in the alphabet with the 'y'. But it is still a different letter, because "symbool" and "royaal" are also valid Dutch words. The situation isn't helped by the fact that some names and words that currently contain an 'ij' used to contain an 'y'.
(Personally I think it's two letters, but there are very serious sources, including a major encyclopedia as well as primary schools, that disagree. In games and puzzles it's also usually considered to be a single letter.)
