There are a lot of characters on the website that don't show up with a name, only their world. If you look at their Free Company list (if they have one) it says "This character has been renamed []. * Former name: (insert character name here)". My character shows up this way and it also says, "This character has been renamed []." in my linkshell list.

Can only assume it is some sort of a bug/glitch given the number of characters that come up like this when searching, but who knows.