What are the specific names for the various username formats in Windows?

When windows users are prompted to enter their username, they can usually specify it in a variety of formats:

• username
• addomain\username

What are the technical terms for each of these? I'd like to know for future reference in case I need a specific format entered.

1 Answer

The info you seek is available from MS here: User Name Formats.

There are actually only two types of user names, "User Principal Name" and "Down-Level Logon Name"

User Principal Name:

User principal name (UPN) format is used to specify an Internet-style name, such as .

Down-Level Logon Name:

The down-level logon name format is used to specify a domain and a user account in that domain, for example, DOMAIN\UserName.

The one where you don't enter a domain name is just using one of these, but it's appending the default domain (or the computer) name for you.