User (Login) Names

User names, also called login names, let users access their own systems and remote systems that have the appropriate access privileges. You must choose a user name for each user account you create. User names must:

• Be unique within your organization, which might span multiple domains

• Contain from two to eight letters and numerals (the first character must be a letter and at least one character must be a lowercase letter)

• Not contain an underscore or space

It is helpful to establish a standard way of forming user names, and the names should be easy for users to remember. A simple scheme when selecting a user name is to use the first name initial and first seven letters of the user's last name. For example, Ziggy Ignatz becomes zignatz. If that scheme results in duplicate names, you can use the first initial, middle initial, and the first six characters of the user's last name. For example, Ziggy Top Ignatz becomes ztignatz. If that still results in duplicate names, you can use the first initial, middle initial, first five characters of the user's last name, and the number 1, or 2, or 3, and so on, until you have a unique name.

Each new user name must be distinct from any mail aliases known to the system or to an NIS or NIS+ domain. Otherwise, mail might be delivered to the alias rather than to the actual user.