There are 4 types of user names created when we hire an employee in the system, this kind of setting we can control vis user category from the security console.
1. Email - It will accept the work email we defined during the hiring process.
2. FirstName.LastName - It will accept the worker's first name and last name.
3. FLastName - It will accept the worker's last name prefixed with the initial of the worker's first name.
4. Person Number - It will accept enterprise uses manual numbering, then any number that you enter becomes the user name. Otherwise, the number is generated automatically and you can't edit it. The automatically generated number becomes the user name.
I hope this blog post was helpful for you. If you have any questions or feedback, please leave a comment below.