With the help of the UI filters some restrictions can be added to certain UI elements of a Riena application. E.g. add a validator to a text field or hide a sub module in the navigation. UI Filters exits of a collection of rules. Is a filter added its rules are applied for the corresponding UI elements. A UI element can be a menu item, a node of the navigation or a ridget. The UI Filters can be composed by adding any kid of rule. The UI filters themselves are added to any node of the navigation. The rules of a filter are only exploited for the node with this filter and all the child nodes. At every time filters can be added to and removed from the navigation model. The changes which are results are immediately visible at the GUI. So the UI filter can be used in a very flexible way and they are also very dynamically. UI Filter An UI filter itself only consists of a collection of rules and an identifier.