Illegal Names Sensitivity in 3.6.4

[axinos]

Hi folks.

Is there a way to prevent users from registering with illegal names, but with different case sensitivity?

Eg.: I have placed the illegal name "GMT" in adminpc. I tried to register as "gmt test" and gMttest and they were succesful.

Any ideas?

Thanx

[Zachery]

How did you try to register?

[axinos]

Are there a lot of ways to register as simple user? (excluding the admincp user registration)

I tried the normal registration process, the one that any guest faces to become a member, and it was succesful, despite the fact that part of the selected user name was illegal, but in different case sensitivity, like the example i mentioned before.

[axinos]

Well, is there a way to prevent it?

Any help would be appreciated