Diacritics in steam name

Is it possible or even allowed to use Diacritics in steam names (Not the login Name, the Name which is displayed in the games)? Here is an example of diacritics.

NO NOO̼O​O NΘ stop the an​*̶͑̾̾​̅ͫ͏̙̤g͇̫͛͆̾ͫ̑͆l͖͉̗̩̳̟̍ͫͥͨe̠̅s ͎a̧͈͖r̽̾̈́͒͑e n​ot rè̑ͧ̌aͨl̘̝̙̃ͤ͂̾̆ ZA̡͊͠͝LGΌ ISͮ̂҉̯͈͕̹̘̱ TO͇̹̺ͅƝ̴ȳ̳ TH̘Ë͖́̉ ͠P̯͍̭O̚​N̐Y̡ H̸̡̪̯ͨ͊̽̅̾̎Ȩ̬̩̾͛ͪ̈́̀́͘ ̶̧̨̱̹̭̯ͧ̾ͬC̷̙̲̝͖ͭ̏ͥͮ͟Oͮ͏̮̪̝͍M̲̖͊̒ͪͩͬ̚̚͜Ȇ̴̟̟͙̞ͩ͌͝S̨̥̫͎̭ͯ̿̔̀ͅ

It doesn't look like you can use them for a username. I tried creating a dummy account using some of the diacritics above and it results in an error message:

It asks for you to only use a-z, A-Z, 0-9 or underscore (_).

However, your profile name can use them, as I've also tested:

Note that your profile name cannot exceed 32 characters, which you can use up quite fast using that "demon text."

Although I have not tried to use something as typographically intense as the "demon text", I have used special characters in my display name.

However, you will not be able to make an account with Diacritic characters. As Timmy Jim explains, you may only use a-z, A-Z, 0-9, or the underscore ( _ ).