Special Chars at Username

[Frank Wallet]

Dear Developers,

on my website i see sometimes member usernames has special characters like * and names with ',"

I want to ask very kindly because i do not have a lot of knowledge about this.

Is it ok to allow usernames or only names with this characters?

thanks.

[Anki]

dear Deverloper,
user names having other character like "'" or any other, makes unsencible, so you should only allow chaterter a-z, A-Z, including no.s in between, and underscore,
you may do this by ajax checker, in your form field
thanks for asking