As you can see in the title and from the xxxHOLiC and Tsubasa RESERVoir CHRoNiCLE Anime News Network Pages pages, the titles for these 2 use mixed casing, on the wikipedia page they have the japanese name as
ツバサ-RESERVoir CHRoNiCLE- Tsubasa: Rezaboa Kuronikuru
I am wondering if there is a reason why the names come out like this?