In tally, when security control is enabled with multiple users list, then the user name is entered with any name. There is no restriction on creating users name in security.
Use of this TDL
Using this tdl, if security control is enabled with multiple users to access particular company, and while using payroll, the list of employees along with their email address will be displayed on users name.
This tdl restricts to use external users or email address, which is not available in the payroll.