Enter a user name, or a regular expression that can match multiple users. You can specify just a user name, or include a client host or domain information. To include a client host with the user name, use the format user@host.
To specify a Windows Active Directory domain, use either a single forward slash or two backward slashes between the domain name and the user name. The following formats are equivalent:
When you omit domain information, the server looks for users defined on the local computer. You can also specify a local user by using the local computer name as the domain name.
Note: User Principal Name (UPN) format is not supported. If you specify "user@host, "host" is always the name of the client computer from which the user connects, not the name of the user's Windows domain.