Cant Change Name with a ?

...So I bought a name change and I go to change my name and I wanna add a ? in it but... when I put a ? in it it says somthing like please make sure there are no spaces (which there isent) and then it says use only .*-_ But the problem is there is alot of players with ? in there name so why cant I change mine to it? did cf take it out or somthing? Please let me know

Thanks.