Name Changes...:(

My original name used to be ShotzChO, then OShotzO, then it was SexyBeast, but when I was in the failed clan =Unity= I changed my name to GlobalUnity...after that I wanted to change my name back to SexyBeast, but when I tried to, it said that the name contained inappropriate language...which is crazy. So I ended up changing it to Shotz*. Now I have been afk for a month now and when I came back my friend Draximus tells me that someone else has the name SexyBeast, with the exact spelling...I was just wondering if this was true that the first name selection has the same language restrictions that the name change has. I know that when you first make a name it has to be more that one letter long...but in the name change you can have a one letter name like K, Z, or X. Can any one help me understand this. xD