Found the following in the help files:

Workstation License Types

The License Manager allows you to see which users and workstations are consuming Report Manager and Report Viewer licenses. A client workstation in an Sage Intelligence Reporting installation can be licensed to run in one of 4 modes. These modes are -  

•Administrator (ADM) - In this mode the workstation can be used to access both the Connector and Sage Intelligence Reporting as well as to run reports from Shortcut files.

•Report Viewer (PR1) - In this mode the workstation can be used to run reports from Shortcut files.

•Request Server (WEB) - In this mode the workstation can be used to access both the Connector Tools and Report Manager as well as to run reports from Shortcut files. Additionally the workstation can run as a Request Server when implemented within The Web Module framework. This mode is only relevant when using The Web Module. For more information please see The Web Module documentation.

•Report Manager (RMG) - In this mode the workstation can be used to access the Report Manager as well as to run reports from Shortcut files.

Thank you!