when i switch to new user, i am unable to see the name in the prompt - why is that?

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http://askubuntu.com – I have just created a fresh installation of ubuntu 12.10 i have created a www-data user account. When I switch to www-data, i cannot see www-data: at the front of the prompt. 1) what is the technical name to call that part of the prompt? 2) how do i make it appear for www-data? See this for reference. as you can see, root has this. but not www-data (HowTos)