Most property values as well as some other information will be saved such as which panes are visible, the window style of the dock manager, the floating location of the dock panes, their widths and heights when they are docked, how they are grouped together. Basically, anything that might be changed by the user at run-time, both through the normal dock manager UI and anything you allow them to control on the dock manager through custom UI, will be saved so their customizations are restored when the application is closed and re-opened.