Objects that appear on page 0 of a form are systematically placed in the background of the current page, the current page being page 1, 2, 3, etc. of the form. When editing a form in the form editor, objects on page 0 cannot be selected when on another page of the form. However, a shortcut can be used to quickly jump to page 0 and select the object, simply Alt+click the object to go to page 0.