A 2003-ban még volt. (de se előtte, se utána nem láttam Windows Server-t úgyhogy nem tudom mikor került be/lett megszüntetve)
The server software can be used in either “per device or per user” mode or “per server” mode. In “per device or per user” mode, you need a Windows Server 2003 CAL for each device or user that directly or indirectly accesses instances of the server software on your licensed servers. In “per server” mode, you need and must dedicate exclusively to an instance of the server software as many Windows Server 2003 CALs as the greatest number of devices and users that may directly or indirectly access that instance at the same time. You may change the mode only one time, from “per server” to “per device or per user.” If you do, you will retain the same number Windows Server 2003 CALs.