Many applications at UW-Madison require a three-character ID for authorization and login purposes.
If you have an employee who needs a three-character login ID, you can request one for the employee here. Note that this request form is protected by Wisconsin Federation and will require that you login with your campus' username and password.
You will need to have the full name, email address, UDDS, and phone number of the new employee available to submit the request.
Once the new employee has received a three-character login, additional authorization requests will need to be submitted for any services that the employee will need. Information about getting authorized for the most common systems can be found here.