In an interactive form that has a fixed layout, header and footer text is usually positioned on the page. When you add subforms that are set to flow content in the form, you typically want header and footer text on the master page.Because the length of an interactive form containing subforms that are set to flow content can expand depending on the amount of data the form contains, additional pages may be added to the form as the end user enters more data. By placing the header and footer on the master pages, you ensure that the header and footer will appear on each page instead of only on the first page.