If it is a requirement to remove the domain\username, or username@domain from the (PMUser, and PMSelfService) login page. This can be modified, or removed by following the workaround below.
This option is only available after selecting the Do not allow users to search for their accounts, and Users must enter their logon names for Identification on the Self-Service site here:
Open the PMAdmin site | General Settings | Search and Logon Options
NOTE: Making changes outside of Support may cause issues with the product. Please ensure you make a backup copy of this file prior to making changes.