SU01 Username special characters

Hello

SAP experts

I know the length of username in SU01 is 12.

But I do not know if all special characters can be used in username.

I had searched lots of documents about special characters of S4HANA Username , Still not get any information.

If someone know about how to use special characters in username of S4HANA, Please share me more information.

Thanks so much.