The IsMinimizedChanged method does not inspect the ACTUAL width of the control

Content is lost when setting IsMinimizable to false and the OutlookBar is minimized

Add a possibility for the vertical resizer to act as the GridSplitter. More information in the support ticket.

The foreground of the MinimizedButton and minimizeable arrow in Expression_Dark theme is wrong. The issue appears when the OutlookBar is minimized and the minimized button is clicked

ItemTemplateSelector does not work. 

There is a workaround to extract the control template and edit the HeaderElement style with:
<ContentControl.ContentTemplateSelector>{TemplateBinding HeaderTemplateSelector}</ContentControl.ContentTemplateSelector>

The problem is fixed and will be available with Lib 2016.3.926.

Add a tooltip to the OutlookBarItems when the OutlookBar is minimized


Approach to implement:

Descriptions of the minimized RadOutlookBarItems can be achieved in WPF via:

<Style TargetType="telerik:RadOutlookBarItem" BasedOn="{StaticResource RadOutlookBarItemStyle}">
    <Style.Triggers>
        <DataTrigger Binding="{Binding RelativeSource={RelativeSource AncestorType={x:Type telerik:RadOutlookBar}}, Path=IsMinimized}" Value="True">
            <Setter Property="ToolTipService.ToolTip" Value="{Binding RelativeSource={RelativeSource Self}, Path=Header}" />
        </DataTrigger>
    </Style.Triggers>
</Style>

or by adding this trigger to the RadOutlookBarItem's ControlTemplate.Triggers

Collapse bar to a slim version, reorganizing the icons to be vertical without description but with hover over descriptions.

Approach to implement:

RadOutlookBar is minimizable by default.
Descriptions of the minimized RadOutlookBarItems can be achieved in WPF via:

<Style TargetType="telerik:RadOutlookBarItem" BasedOn="{StaticResource RadOutlookBarItemStyle}">
    <Style.Triggers>
        <DataTrigger Binding="{Binding RelativeSource={RelativeSource AncestorType={x:Type telerik:RadOutlookBar}}, Path=IsMinimized}" Value="True">
            <Setter Property="ToolTipService.ToolTip" Value="{Binding RelativeSource={RelativeSource Self}, Path=Header}" />
        </DataTrigger>
    </Style.Triggers>
</Style>

or by adding this trigger to the RadOutlookBarItem's ControlTemplate.Triggers

Add Style for easier customization of the Vertical / Horizontal resizers

You can work this around by extracting the RadOutlookBar style and slightly modify it. You can find the Grid panel that holds the title and the minimize button and position the elements in different columns. 
 
<!-- Other XAML from the template -->
<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition />
        <ColumnDefinition />
    </Grid.ColumnDefinitions>
    <ContentControl x:Name="TitleElement" ContentTemplate="{TemplateBinding TitleTemplate}" Foreground="#FFDDDDDD"
                    FontWeight="Bold" HorizontalContentAlignment="Stretch" IsTabStop="False" Margin="5,3"
                    VerticalAlignment="Center" VerticalContentAlignment="Center"/>
    <telerik:RadToggleButton x:Name="MinimizeButton" Grid.Column="1"
                             IsChecked="{Binding IsMinimized, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}"
                             Style="{TemplateBinding MinimizeButtonStyle}">
        <telerik:RadToggleButton.Visibility>
            <Binding Path="IsMinimizable" RelativeSource="{RelativeSource TemplatedParent}">
                <Binding.Converter>
                    <telerik:BooleanToVisibilityConverter/>
                </Binding.Converter>
            </Binding>
        </telerik:RadToggleButton.Visibility>
    </telerik:RadToggleButton>
</Grid>
<!-- Other XAML from the template -->

Another approach is to use the ChildrenOfTypeExtensions.ChildrenOfType<T>() method to get the Grid and the minimize button, and add set the required properties. Here is an example:

private void outlookBar_Loaded(object sender, RoutedEventArgs e)
{
    var minimizeButton = this.outlookBar.ChildrenOfType<RadToggleButton>().FirstOrDefault(x => x.Name == "MinimizeButton");
    if (minimizeButton != null)
    {
        var parentGrid = minimizeButton.ParentOfType<Grid>();
        parentGrid.ColumnDefinitions.Add(new ColumnDefinition());
        parentGrid.ColumnDefinitions.Add(new ColumnDefinition());
        Grid.SetColumn(minimizeButton, 1);
    }
}

The control is not translated in German

Reason for declination: 
The XAML team has recently reviewed this issue and it cannot be reproduced by following the described steps in our help:
http://docs.telerik.com/devtools/silverlight/common-localization.html#localization-using-built-in-resources
If you still encounter this issue and it is blocking for your work please contact us through the support ticketing system with details on your setup and a reference to this item. 

If you set the SmallIcon property of a RadOutlookBarItem and you minimize the item the icon will not be visualized. Note that the icon is not visualized when a certain item goes in the popup.