The IBM Session Manager Shared User facility enables multiple users to login with the same userid (for details, see the IBM Session Manager Installation and Customization manual).
For each user a unique, or fully qualified, identifier is created internally by appending a 'user qualifier' to the userid. Depending on the value of parameter MULTUSER on the SYSTEM statement, either the 'user qualifier' is created from the last four characters of the terminal LU name, or it is an eight-digit number in the range 1-99999999.
If a user logs in to IBM Session Manager through the IBM Session Manager Plug-in then that user will automatically be set as a Shared user, therefore allowing the same user to be logged in at the same time to the IBM Session Manager Plug-in and (directly) to IBM Session Manager.