The Control to open the menu in the sidebar that contains options such as Customization, Undock, and Close Sidebar is formatted as a checkbox and has no label for assistive technologies. To place assistive technology focus on this toolbar. Press F6 to move to the sidebar. and then Use the Arrow keys to focus the checkbox. This is located above the Properties radio button that is located in the group of selectable sidebar sections
*** This bug has been marked as a duplicate of bug 102033 ***