In a preferred embodiment, the user interface has a UI allocation table or can generate a temporary UI allocation table. A media ID is assigned to at least one identifier in the UI allocation table. Preferably, several identifiers are contained in the UI allocation table, at least one media ID being assigned to the respective identifier in the UI allocation table. In a preferred embodiment, in all the described embodiments, the UI allocation table is queried instead of the server allocation table being queried. In this way, steps can advantageously be conducted that would in any case require a connection to the server, even if a connection cannot or should not be established, or cannot or should not be established with sufficient speed or quality.
In a preferred embodiment, the user interface has a UI user maintenance routine. The UI user maintenance routine can transmit a user maintenance signal. The user maintenance signal can include a user and a user group. By sending the user maintenance signal, the server receiving such a user maintenance signal can be prompted to change the assignment of users to a user group in the user group table.
In a preferred embodiment, the user maintenance signal can contain an e-mail address. When executing the UI user maintenance routine, the user can be asked by the UI, for example by a GUI of a UI, to enter an e-mail address.