{{Attention|Please be careful when you enable undo and redo. Because {{key press|Ctrl}} + {{key press|Z}} (or whichever other combination in your keyboard layout) is the shortcut to trigger an undo. Therefore, it's possible that you accidentally undo/revert your changes in the PDF viewer when you are typing.}}
* The default stroke width for Annotations can be defined with the AnnotationDefaultStrokeWidth property in the UBIKThemes.xaml:
<source lang = "xml">
<x:Double x:Key="AnnotationDefaultStrokeWidth">1</x:Double>
</source>
</tab>